The Whispers of Thieves

Whenever one or more creatures an opponent
controls attack, you may pay {1} to investigate.
Clues you control have "{t}, sacrifice this token:
Surveil 1.", "{t}: Look at target face-down card
on the battlefield or in exile." And "{u/b}{u/b}, {t},
sacrifice this token: Name a card, then reveal
target face-down card on the battlefield or in
exile. If the named card is revealed, you may put
it into its owner's library second from the top
unless that player reveals their hand."