Mountain

Suspicious Detonation

This spell costs {3} less to cast if you've sacrificed an artifact this turn.
This spell can't be countered. (This includes by the ward ability.)
Suspicious Detonation deals 4 damage to target creature.

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.

Dramatic Accusation

Enchant creature
When Dramatic Accusation enters, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.
{U}{U}: Shuffle enchanted creature into its owner's library.

Behind the Mask

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.)
Until end of turn, target artifact or creature becomes an artifact creature with base power and toughness 4/3. If evidence was collected, it has base power and toughness 1/1 until end of turn instead.

Clue

{2}, Sacrifice this artifact: Draw a card.

Red Herring

Haste
Red Herring attacks each combat if able.
{2}, Sacrifice Red Herring: Draw a card.

Crime Novelist

Whenever you sacrifice an artifact, put a +1/+1 counter on Crime Novelist and add {R}.

Thopter

Harried Dronesmith

At the beginning of combat on your turn, create a 1/1 colorless Thopter artifact creature token with flying. It gains haste until end of turn. Sacrifice it at the beginning of your next end step.

Cornered Crook

When Cornered Crook enters, you may sacrifice an artifact. When you do, Cornered Crook deals 3 damage to any target.

Reckless Detective

Whenever Reckless Detective attacks, you may sacrifice an artifact or discard a card. If you do, draw a card and Reckless Detective gets +2/+0 until end of turn.

Reasonable Doubt

Counter target spell unless its controller pays {2}.
Suspect up to one target creature. (A suspected creature has menace and can't block.)

Public Thoroughfare

Public Thoroughfare enters tapped.
When Public Thoroughfare enters, sacrifice it unless you tap an untapped artifact or land you control.
{T}: Add one mana of any color.

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.

Island

Furtive Courier

Furtive Courier can't be blocked as long as you've sacrificed an artifact this turn.
Whenever Furtive Courier attacks, draw a card, then discard a card.

Bother

Create three 1/1 colorless Thopter artifact creature tokens with flying. Surveil 2.

Fuss

Put a +1/+1 counter on each attacking creature you control.

Fuss // Bother

Gleaming Geardrake

Flying
When Gleaming Geardrake enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")
Whenever you sacrifice an artifact, put a +1/+1 counter on Gleaming Geardrake.

Gadget Technician

When Gadget Technician enters or is turned face up, create a 1/1 colorless Thopter artifact creature token with flying.
Disguise {U/R}{U/R} (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.)

Magnifying Glass

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