Nelly Borca, Impulsive Accuser

Vigilance
Whenever Nelly Borca, Impulsive Accuser attacks, suspect target creature. Then goad all suspected creatures. (A suspected creature has menace and can't block.)
Whenever one or more creatures an opponent controls deal combat damage to one or more of your opponents, you and the controller of those creatures each draw a card.

Undercover Crocodelf

Whenever Undercover Crocodelf deals combat damage to a player, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")
Disguise {3}{G/U}{G/U} (You may cast this card face down for {3} as a 2/2 creature with ward {2}. Turn it face up any time for its disguise cost.)

Sunken Hollow

({T}: Add {U} or {B}.)
Sunken Hollow enters tapped unless you control two or more basic lands.

Detective of the Month

Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.)
As long as you have the city's blessing, Detectives you control can't be blocked.
Whenever you draw your second card each turn, create a 2/2 white and blue Detective creature token.

Evidence Examiner

At the beginning of combat on your turn, you may collect evidence 4. (Exile cards with total mana value 4 or greater from your graveyard.)
Whenever you collect evidence, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Conservatory

Conservatory enters tapped.
{T}: Add {G} or {W}.
{4}, {T}: Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Fellwar Stone

{T}: Add one mana of any color that a land an opponent controls could produce.

Forensic Gadgeteer

Whenever you cast an artifact spell, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")
Activated abilities of artifacts you control cost {1} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Agency Outfitter

Flying
When Agency Outfitter enters, you may search your graveyard, hand and/or library for a card named Magnifying Glass and/or a card named Thinking Cap and put them onto the battlefield. If you search your library this way, shuffle.

Perimeter Enforcer

Flying, lifelink
Whenever another Detective you control enters and whenever a Detective you control is turned face up, Perimeter Enforcer gets +1/+1 until end of turn.

Morophon, the Boundless

Changeling (This card is every creature type.)
As Morophon, the Boundless enters, choose a creature type.
Spells of the chosen type you cast cost {W}{U}{B}{R}{G} less to cast. This effect reduces only the amount of colored mana you pay.
Other creatures you control of the chosen type get +1/+1.

Tiny

Wojek Investigator

Flying, vigilance
At the beginning of your upkeep, investigate once for each opponent who has more cards in hand than you. (To investigate, create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Secret Passage

Secret Passage enters tapped.
{T}: Add {U} or {B}.
{4}, {T}: Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Private Eye

Other Detectives you control get +1/+1.
Whenever you draw your second card each turn, target Detective can't be blocked this turn.

Prairie Stream

({T}: Add {W} or {U}.)
Prairie Stream enters tapped unless you control two or more basic lands.

Billiard Room

Billiard Room enters tapped.
{T}: Add {B} or {R}.
{4}, {T}: Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Mountain

Path of Ancestry

Path of Ancestry enters tapped.
{T}: Add one mana of any color in your commander's color identity. When that mana is spent to cast a creature spell that shares a creature type with your commander, scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Kaust, Eyes of the Glade

Whenever a creature you control that was turned face up this turn deals combat damage to a player, draw a card.
{T}: Turn target face-down attacking creature you control face up.

Lonis, Genetics Expert

Evolve (Whenever a creature you control enters, if that creature has greater power or toughness than this creature, put a +1/+1 counter on this creature.)
Whenever one or more +1/+1 counters are put on Lonis, investigate that many times.
Whenever you sacrifice a Clue, put a +1/+1 counter on another target creature you control.

Magnifying Glass

{T}: Add {C}.
{4}, {T}: Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Guardian Project

Whenever a nontoken creature you control enters, if it doesn't have the same name as another creature you control or a creature card in your graveyard, draw a card.

Watery Grave

({T}: Add {U} or {B}.)
As Watery Grave enters, you may pay 2 life. If you don't, it enters tapped.

Dining Room

Dining Room enters tapped.
{T}: Add {R} or {G}.
{4}, {T}: Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Temple Garden

({T}: Add {G} or {W}.)
As Temple Garden enters, you may pay 2 life. If you don't, it enters tapped.

Novice Inspector

When Novice Inspector enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Orzhov Basilica

Orzhov Basilica enters tapped.
When Orzhov Basilica enters, return a land you control to its owner's hand.
{T}: Add {W}{B}.

Hallowed Fountain

({T}: Add {W} or {U}.)
As Hallowed Fountain enters, you may pay 2 life. If you don't, it enters tapped.

Detective's Satchel

When Detective's Satchel enters, investigate twice. (To investigate, create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")
{T}: Create a 1/1 colorless Thopter artifact creature token with flying. Activate only if you've sacrificed an artifact this turn.

Tail the Suspect

Investigate. You may play an additional land this turn. (Then exile this card. You may cast the creature later from exile.)

Kellan, Inquisitive Prodigy

Flying, vigilance
Whenever Kellan, Inquisitive Prodigy attacks, destroy up to one target artifact. If you controlled that permanent, draw a card.

Kellan, Inquisitive Prodigy // Tail the Suspect

Kitchen

Kitchen enters tapped.
{T}: Add {G} or {U}.
{4}, {T}: Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Duggan, Private Detective

Duggan's power and toughness are each equal to the number of cards in your hand.
Whenever Duggan enters or attacks, investigate.
The Most Important Punch in History — {1}{G}, {T}: Duggan deals damage equal to twice its power to another target creature. Activate only once.

Lounge

Lounge enters tapped.
{T}: Add {B} or {G}.
{4}, {T}: Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Case of the Filched Falcon

When this Case enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")
To solve — You control three or more artifacts. (If unsolved, solve at the beginning of your end step.)
Solved — {2}{U}, Sacrifice this Case: Put four +1/+1 counters on target noncreature artifact. It becomes a 0/0 Bird creature with flying in addition to its other types.

Forest

Arcane Signet

Innocuous Researcher

Parley — Whenever Innocuous Researcher attacks, each player reveals the top card of their library. For each nonland card revealed this way, you investigate. Then each player draws a card.
At the beginning of your end step, you may untap all lands you control. If you do, you can't cast spells until your next turn.

Alquist Proft, Master Sleuth

Vigilance
When Alquist Proft, Master Sleuth enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")
{X}{W}{U}{U}, {T}, Sacrifice a Clue: You draw X cards and gain X life.

Blood Crypt

({T}: Add {B} or {R}.)
As Blood Crypt enters, you may pay 2 life. If you don't, it enters tapped.

Exit Specialist

Exit Specialist can't be blocked by creatures with power 3 or greater.
Disguise {1}{U} (You may cast this card face down for {3} as a 2/2 creature with ward {2}. Turn it face up any time for its disguise cost.)
When Exit Specialist is turned face up, return another target creature to its owner's hand.

Azorius Chancery

Azorius Chancery enters tapped.
When Azorius Chancery enters, return a land you control to its owner's hand.
{T}: Add {W}{U}.

Hedge Maze

({T}: Add {G} or {U}.)
Hedge Maze enters tapped.
When Hedge Maze enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Felonious Rage

Target creature you control gets +2/+0 and gains haste until end of turn. When that creature dies this turn, create a 2/2 white and blue Detective creature token.

Godless Shrine

({T}: Add {W} or {B}.)
As Godless Shrine enters, you may pay 2 life. If you don't, it enters tapped.

Case of the Shifting Visage

At the beginning of your upkeep, surveil 1.
To solve — There are fifteen or more cards in your graveyard. (If unsolved, solve at the beginning of your end step.)
Solved — Whenever you cast a nonlegendary creature spell, copy that spell. (The copy becomes a token.)

Homicide Investigator

Whenever one or more nontoken creatures you control die, investigate. This ability triggers only once each turn. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Smothering Tithe

Whenever an opponent draws a card, that player may pay {2}. If the player doesn't, you create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Jungle Shrine

Jungle Shrine enters tapped.
{T}: Add {R}, {G}, or {W}.

Tenth District Hero

{1}{W}, Collect evidence 2: Tenth District Hero becomes a Human Detective with base power and toughness 4/4 and gains vigilance.
{2}{W}, Collect evidence 4: If Tenth District Hero is a Detective, it becomes a legendary creature named Mileva, the Stalwart, it has base power and toughness 5/5, and it gains "Other creatures you control have indestructible."

Choked Estuary

As Choked Estuary enters, you may reveal an Island or Swamp card from your hand. If you don't, Choked Estuary enters tapped.
{T}: Add {U} or {B}.

Agrus Kos, Spirit of Justice

Double strike, vigilance
Whenever Agrus Kos, Spirit of Justice enters or attacks, choose up to one target creature. If it's suspected, exile it. Otherwise, suspect it. (A suspected creature has menace and can't block.)

Case of the Trampled Garden

When this Case enters, distribute two +1/+1 counters among one or two target creatures you control.
To solve — Creatures you control have total power 8 or greater. (If unsolved, solve at the beginning of your end step.)
Solved — Whenever you attack, put a +1/+1 counter on target attacking creature. It gains trample until end of turn.

Furycalm Snarl

As Furycalm Snarl enters, you may reveal a Mountain or Plains card from your hand. If you don't, Furycalm Snarl enters tapped.
{T}: Add {R} or {W}.

Inside Source

When Inside Source enters, create a 2/2 white and blue Detective creature token.
{3}, {T}: Target Detective you control gets +2/+0 and gains vigilance until end of turn. Activate only as a sorcery.

Person of Interest

When Person of Interest enters, suspect it. Create a 2/2 white and blue Detective creature token. (A suspected creature has menace and can't block.)

Sheltered Thicket

({T}: Add {R} or {G}.)
Sheltered Thicket enters tapped.
Cycling {2} ({2}, Discard this card: Draw a card.)

Stomping Ground

({T}: Add {R} or {G}.)
As Stomping Ground enters, you may pay 2 life. If you don't, it enters tapped.

Case of the Ransacked Lab

Instant and sorcery spells you cast cost {1} less to cast.
To solve — You've cast four or more instant and sorcery spells this turn. (If unsolved, solve at the beginning of your end step.)
Solved — Whenever you cast an instant or sorcery spell, draw a card.

Raucous Theater

({T}: Add {B} or {R}.)
Raucous Theater enters tapped.
When Raucous Theater enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Case the Joint

Draw two cards, then look at the top card of each player's library.

Propaganda

Creatures can't attack you unless their controller pays {2} for each creature they control that's attacking you.

Simic Growth Chamber

Simic Growth Chamber enters tapped.
When Simic Growth Chamber enters, return a land you control to its owner's hand.
{T}: Add {G}{U}.

Melek, Reforged Researcher

Melek, Reforged Researcher's power and toughness are each equal to twice the number of instant and sorcery cards in your graveyard.
The first instant or sorcery spell you cast each turn costs {3} less to cast.

Hall

Hall enters tapped.
{T}: Add {R} or {W}.
{4}, {T}: Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Persuasive Interrogators

When Persuasive Interrogators enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")
Whenever you sacrifice a Clue, target opponent gets two poison counters. (A player with ten or more poison counters loses the game.)

Case of the Gateway Express

When this Case enters, choose target creature you don't control. Each creature you control deals 1 damage to that creature.
To solve — Three or more creatures attacked this turn. (If unsolved, solve at the beginning of your end step.)
Solved — Creatures you control get +1/+0.

Mirko, Obsessive Theorist

Flying, vigilance
Whenever you surveil, put a +1/+1 counter on Mirko, Obsessive Theorist.
At the beginning of your end step, you may return target creature card with power less than Mirko's from your graveyard to the battlefield with a finality counter on it. (If it would die, exile it instead.)

Case of the Gorgon's Kiss

When this Case enters, destroy up to one target creature that was dealt damage this turn.
To solve — Three or more creature cards were put into graveyards from anywhere this turn. (If unsolved, solve at the beginning of your end step.)
Solved — This Case is a 4/4 Gorgon creature with deathtouch and lifelink in addition to its other types.

Crimestopper Sprite

As an additional cost to cast this spell, you may collect evidence 6. (Exile cards with total mana value 6 or greater from your graveyard.)
Flying
When Crimestopper Sprite enters, tap target creature. If evidence was collected, put a stun counter on it. (If a permanent with a stun counter would become untapped, remove one from it instead.)

Lush Portico

({T}: Add {G} or {W}.)
Lush Portico enters tapped.
When Lush Portico enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Carnage Interpreter

When Carnage Interpreter enters, discard your hand, then investigate four times. (To investigate, create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")
As long as you have one or fewer cards in hand, Carnage Interpreter gets +2/+2 and has menace.

Meticulous Archive

({T}: Add {W} or {U}.)
Meticulous Archive enters tapped.
When Meticulous Archive enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Final-Word Phantom

Flash
Flying
During each opponent's end step, you may cast spells as though they had flash.

Rhystic Study

Whenever an opponent casts a spell, you may draw a card unless that player pays {1}.

Swamp

Escape Tunnel

{T}, Sacrifice Escape Tunnel: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
{T}, Sacrifice Escape Tunnel: Target creature with power 2 or less can't be blocked this turn.

Cold Case Cracker

Flying
When Cold Case Cracker dies, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Library

Library enters tapped.
{T}: Add {U} or {R}.
{4}, {T}: Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Sacred Foundry

({T}: Add {R} or {W}.)
As Sacred Foundry enters, you may pay 2 life. If you don't, it enters tapped.

Access Tunnel

{T}: Add {C}.
{3}, {T}: Target creature with power 3 or less can't be blocked this turn.

Memory Vampire

Flying
Whenever Memory Vampire deals combat damage to a player, any number of target players each mill that many cards. Then you may collect evidence 9. When you do, you may cast target nonland card from defending player's graveyard without paying its mana cost.

Museum Nightwatch

When Museum Nightwatch dies, create a 2/2 white and blue Detective creature token.
Disguise {1}{W} (You may cast this card face down for {3} as a 2/2 creature with ward {2}. Turn it face up any time for its disguise cost.)

Burden of Proof

Flash
Enchant creature
Enchanted creature gets +2/+2 as long as it's a Detective you control. Otherwise, it has base power and toughness 1/1 and can't block Detectives.

Boros Garrison

Boros Garrison enters tapped.
When Boros Garrison enters, return a land you control to its owner's hand.
{T}: Add {R}{W}.

Golgari Rot Farm

Golgari Rot Farm enters tapped.
When Golgari Rot Farm enters, return a land you control to its owner's hand.
{T}: Add {B}{G}.

Selesnya Sanctuary

Selesnya Sanctuary enters tapped.
When Selesnya Sanctuary enters, return a land you control to its owner's hand.
{T}: Add {G}{W}.

Forensic Researcher

{T}: Untap another target permanent you control.
{T}, Collect evidence 3: Tap target creature you don't control. (To collect evidence 3, exile cards with total mana value 3 or greater from your graveyard.)

Dimir Aqueduct

Dimir Aqueduct enters tapped.
When Dimir Aqueduct enters, return a land you control to its owner's hand.
{T}: Add {U}{B}.

Academy Manufactor

If you would create a Clue, Food, or Treasure token, instead create one of each.

Case File Auditor

When Case File Auditor enters and whenever you solve a Case, look at the top six cards of your library. You may reveal an enchantment card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.
You may spend mana as though it were mana of any color to cast Case spells.

Case of the Pilfered Proof

Whenever a Detective you control enters or is turned face up, put a +1/+1 counter on it.
To solve — You control three or more Detectives. (If unsolved, solve at the beginning of your end step.)
Solved — If one or more tokens would be created under your control, those tokens plus a Clue token are created instead. (It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Madame Vastra

Partner with Jenny Flint (When this creature enters, target player may put Jenny Flint into their hand from their library, then shuffle.)
Madame Vastra must be blocked if able.
Whenever a creature dealt damage by Madame Vastra this turn dies, create a Clue token and a Food token.

Island

Lazav, Wearer of Faces

Whenever Lazav, Wearer of Faces attacks, exile target card from a graveyard, then investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")
Whenever you sacrifice a Clue, you may have Lazav become a copy of a creature card exiled with it until end of turn.

Underground Mortuary

({T}: Add {B} or {G}.)
Underground Mortuary enters tapped.
When Underground Mortuary enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Izzet Boilerworks

Izzet Boilerworks enters tapped.
When Izzet Boilerworks enters, return a land you control to its owner's hand.
{T}: Add {U}{R}.

Cinder Glade

({T}: Add {R} or {G}.)
Cinder Glade enters tapped unless you control two or more basic lands.

Chalk Outline

Whenever one or more creature cards leave your graveyard, create a 2/2 white and blue Detective creature token, then investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Izoni, Center of the Web

Menace
Whenever Izoni, Center of the Web enters or attacks, you may collect evidence 4. If you do, create two 2/1 black and green Spider creature tokens with menace and reach.
Sacrifice four tokens: Surveil 2, then draw two cards. You gain 2 life.