This is a fantastic trick!
The magician places a deck of cards (Bicycle) and a plastic case on the table. He takes a card out of the deck and shows it to the audience, asking them to remember it (10 of diamonds). He then returns it to the deck and puts the entire deck into the plastic case. After a magic snap the magician throws the case into the air and the deck of cards vanishes from the case, leaving only the 10 of diamonds!
Very effective trick!