Unexplained Disappearance
Instant
Return target creature to its owner's hand.
Surveil 1. (Look at the top card of your library. You may put that card into your graveyard.)
The first thing the mist chills is the mind. Victims never cry out or even murmur in surprise.
Izzy
Guilds of Ravnica (GRN)
• #56Rulings
Some spells that instruct you to surveil require targets. You can't cast a spell without choosing legal targets. If all of those targets become illegal, the spell doesn't resolve and you won't surveil.
(wotc • 2024-01-12)
You perform the actions stated on a card in sequence. For some spells and abilities, you'll surveil last. For others, you'll surveil and then perform other actions.
(wotc • 2024-01-12)
Rulings
Some spells that instruct you to surveil require targets. You can't cast a spell without choosing legal targets. If all of those targets become illegal, the spell doesn't resolve and you won't surveil.
(wotc • 2024-01-12)
You perform the actions stated on a card in sequence. For some spells and abilities, you'll surveil last. For others, you'll surveil and then perform other actions.
(wotc • 2024-01-12)