You play Scrying Pool. When your opponent clicks on their reaction card, a bug in the Making Fun client causes their game to crash. They quit the game while they still have priority, and the game ends before you can draw your card.
Or one person resigns before you can draw the card.
Edit: I suppose the answer isn't just "You have one card in your deck - it's the Scrying Pool you just played"
Correct. To clarify: you play your SP, opponent has a Secret Chamber or something in hand, then they realize just how far behind they are and resign. Game ends, with you having never drawn that card.
EDIT: there's also a way with Possession (though Possession was outlawed by the OP):
I, P1, am possessing my opponent, P2. P2 (as me) plays SP. I reveal P2's only card in deck, discard it, then reveal P1's top card which is a Tunnel, and discard it. I (P2) gain the Gold, and then I draw it instead of the other card.