Hi, im new to theory11 I am curious how this one trick works, you show an all blank deck (both sdes of cards) and tell the spectator to choose any card, you hand them a double blank card saying its their card, and then a pile of them. You put their card in the middle of the pile, which is entirely blank. and in the end of it you reveal that their card is the only printed card in the deck. Its been racking my brain for a week. Its not an invisible deck by the way.