Fleeting Memories

When this enchantment enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.")
Whenever you sacrifice a Clue, target player mills three cards.

Shadows over Innistrad Remastered

When Fleeting Memories enters the battlefield, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")
Whenever you sacrifice a Clue, target player mills three cards.

Shadows over Innistrad

When Fleeting Memories enters the battlefield, investigate. (Put a colorless Clue artifact token onto the battlefield with "{2}, Sacrifice this artifact: Draw a card.")
Whenever you sacrifice a Clue, target player puts the top three cards of his or her library into his or her graveyard.

Clue is an artifact type. Even though it appears on some cards with other permanent types, it's never a creature type, a land type, or anything but an artifact type.

If an effect refers to a Clue, it means any Clue artifact, not just a Clue artifact token. For example, you can sacrifice Wrench to pay for Alquist Proft, Master Sleuth's activated ability.

If you sacrifice a Clue to pay the cost of a spell or ability, Fleeting Memories's second ability will resolve before that spell or ability.

You can't sacrifice a Clue to pay multiple costs. For example, you can't sacrifice a Clue token to activate its own ability and also to activate Alquist Proft, Master Sleuth's ability.