Catapult
At the end of each of your turns, you may choose a card that's currently in your hand and a Pile in any YARD. Trash the card that you chose from your hand. Turn the Pile that you chose to its DIRT side, and then trash all of the cards that are on top of that Pile.
You can pick any card from your hand to trash.
You must trash a card from your hand, otherwise you cannot do the rest of the action.
The Pile can be in any YARD, regardless of whether the owner is HOME or AWAY.
You can pick a Pile in your own YARD (including the one that your CATAPULT is on, if you should so desire to trash your own CATAPULT.)
This action triggers at the end of your turn, regardless of whether you're HOME or AWAY.