Gravestone Strider

{1}: Add one mana of any color. Activate only once each turn.
{2}, Exile Gravestone Strider from your graveyard: Exile target card from a graveyard.

Mountain

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.

Knife

During your turn, equipped creature gets +1/+0 and has first strike.
{2}, Sacrifice Knife: Draw a card.
Equip {2}

Connecting the Dots

Whenever a creature you control attacks, exile the top card of your library face down. (You can't look at it.)
{1}{R}, Discard your hand, Sacrifice Connecting the Dots: Put all cards exiled with Connecting the Dots into their owners' hands.

Sanitation Automaton

When Sanitation Automaton enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Demand Answers

As an additional cost to cast this spell, sacrifice an artifact or discard a card.
Draw two cards.

Crime Novelist

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

Cryptex

{T}, Collect evidence 3: Add one mana of any color. Put an unlock counter on Cryptex. (To collect evidence 3, exile cards with total mana value 3 or greater from your graveyard.)
Sacrifice Cryptex: Surveil 3, then draw three cards. Activate only if Cryptex has five or more unlock counters on it.

Shock

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.

Case of the Crimson Pulse

When this Case enters, discard a card, then draw two cards.
To solve — You have no cards in hand. (If unsolved, solve at the beginning of your end step.)
Solved — At the beginning of your upkeep, discard your hand, then draw two cards.

Caught Red-Handed

This spell can't be countered. (This includes by the ward ability.)
Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn. Suspect it. (It has menace and can't block.)

Lumbering Laundry

{2}: Until end of turn, you may look at face-down creatures you don't control any time.
Disguise {5} (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.)

Frantic Scapegoat

Haste
When Frantic Scapegoat enters, suspect it. (It has menace and can't block.)
Whenever one or more other creatures you control enter, if Frantic Scapegoat is suspected, you may suspect one of the other creatures. If you do, Frantic Scapegoat is no longer suspected.

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.

Rubblebelt Braggart

Whenever Rubblebelt Braggart attacks, if it's not suspected, you may suspect it. (A suspected creature has menace and can't block.)

Magnetic Snuffler

When Magnetic Snuffler enters, return target Equipment card from your graveyard to the battlefield attached to Magnetic Snuffler.
Whenever you sacrifice an artifact, put a +1/+1 counter on Magnetic Snuffler.

The Chase Is On

Target creature gets +3/+0 and gains first strike until end of turn. Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Gearbane Orangutan

Reach
When Gearbane Orangutan enters, choose one —
• Destroy up to one target artifact.
• Sacrifice an artifact. If you do, put two +1/+1 counters on Gearbane Orangutan.

Red Herring

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

Expedited Inheritance

Whenever a creature is dealt damage, its controller may exile that many cards from the top of their library. They may play those cards until the end of their next turn.

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.

Case of the Burning Masks

When this Case enters, it deals 3 damage to target creature an opponent controls.
To solve — Three or more sources you controlled dealt damage this turn. (If unsolved, solve at the beginning of your end step.)
Solved — Sacrifice this Case: Exile the top three cards of your library. Choose one of them. You may play that card this turn.

Cornered Crook

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

Vengeful Tracker

Whenever an opponent sacrifices an artifact, Vengeful Tracker deals 2 damage to them.

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.)

Concealed Weapon

Equipped creature gets +3/+0.
Disguise {2}{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.)
When Concealed Weapon is turned face up, attach it to target creature you control.
Equip {1}{R}

Torch the Witness

Torch the Witness deals twice X damage to target creature. If excess damage was dealt to that creature this way, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Innocent Bystander

Whenever Innocent Bystander is dealt 3 or more damage, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Magnifying Glass

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

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.

Galvanize

Galvanize deals 3 damage to target creature. If you've drawn two or more cards this turn, Galvanize deals 5 damage to that creature instead.