Unexplained Disappearance

Bounce spells have always lived in a strange place on the tempo curve: they undo a creature for a turn without permanently answering it, so the question is whether the extra mana buys anything besides the delay. Here the answer is a card-selection rider bolted onto a familiar return-to-hand effect, and because it happens at instant speed, the two mana can be held up and spent reactively rather than committed on your own turn. The surveil resolves after the bounce, which matters more than the small number suggests: you get to look before you commit your next draw, smoothing the screw or flood that punishes a deck spending mana to reset the board instead of developing it. That smoothing is also the rider's whole justification; the dig costs nothing but the second mana, and it feeds the graveyard in a way a scry never could, which is the design throughline of surveil as a keyword. The catch is that the creature comes right back, so the spell wants to be cast at the moment the round-trip earns more than the card it sets aside: re-triggering an enters-the-battlefield ability, saving a creature from a removal spell mid-stack, undoing a freshly resolved aura. As fair-interaction bounce goes, it is honest: a real target restriction (creature only), instant timing, and a rider that quietly improves your hand instead of your board.