If a unit with a hidden Zhonya's is the only thing I control on a battlefield and I move it back to base, what happens to the Zhonya's?

Ruling: You must reveal Zhonya's before moving the unit back to base. If you move the unit first, you immediately lose control of the battlefield and the hidden card goes to the trash without an opportunity to activate it.

Sequence:

• First, reveal the Zhonya's
• Then it will be recalled
• Then you can move the unit back to base

Nuances:

• During your own turn, you can play hidden cards (like reactions) at any time, not just in response to something
• During your opponent's turn, you can only play reactions if there's a chain or showdown
• However, during your opponent's turn, your unit can't move without a chain anyway, so you always have an opportunity to play the Zhonya's before the effect resolves