Knowledge Vault

Artifact

, : Exile the top card of your library face down.

: Sacrifice this artifact. If you do, discard your hand, then put all cards exiled with this artifact into their owner's hand.

When this artifact leaves the battlefield, put all cards exiled with it into their owner's graveyard.

Knowledge Vault is on the reserved list, which means WOTC has self-imposed restrictions from making functional reprints of this card.