Encantamiento
Cuando los Recuerdos fugaces entren al campo de batalla, investiga. (Pon en el campo de batalla una ficha de artefacto Pista incolora con "

, sacrificar este artefacto: Roba una carta".)
Siempre que sacrifiques una Pista, el jugador objetivo pone las tres primeras cartas de su biblioteca en su cementerio.
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.
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.
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.