From a shuffled and borrowed deck the spectator takes two packets, shuffles them and looks at the card on the bottom of each. The magician never touches the deck.
The spectator puts the packets back on top of the rest of the deck.
Under truly impossible conditions the magician is able to divine in which positions the chosen cards are.

Impromptu! With a borrowed shuffled deck!
A magician fooler!

NO GIMMICK