Cast zone rules

Any card can be placed in a Cast Zone from your
hand face down during your main phase (this
doesn't count as casting the card.) You cast them
from here as you would from your hand. You may
look at these cards as if they were a part of your hand.
If a Cast Zone is removed from the battlefield, all
cards in it are destroyed. If there were to be more
cards in a cast zone than it's maximum, the owner
must return cards to their hand until the maximum
is no longer crossed.