Rewind {2}{U}{U}

Instant

Counter target spell. Untap up to four lands.

Prints	USD	EUR	TIX
The List	$0.24
Secret Lair Drop #1368	$2.92
Secret Lair Drop #1036	$5.21
Core Set 2021	$0.21	€0.48	0.03
Modern Masters 2017	$0.27	€0.20	0.03
Magic Online Promos			0.05
Magic 2013	$0.32	€0.20	0.03
Ninth Edition #94	$0.35	€0.19	0.03
Ninth Edition #94★	✶ $2.76
World Champ Decks 2004	$0.59	€0.34
View all prints →

Rewind targets only a spell. It doesn't target any lands. The lands are chosen as Rewind resolves. (2020-06-23)
You can choose up to four lands, no matter who controls any of them. Those lands untap once. You can't choose one land and have it untap four times, for example. (2020-06-23)

If the spell is an illegal target when Rewind tries to resolve, perhaps because it was countered by another spell or ability, Rewind won't resolve and none of its effects will happen. You won't untap any lands. (2020-06-23)