Trick Deck by Uday - Trick

Two blank cards and the 4 of Hearts and 4 of Clubs are shown, front and back. The two fours are placed into a unprepared envelope which is then sealed. The two blanks are dropped into an empty container. The performer causes the spots on the two cards in the envelope held by a spectator to travel to the blank cards in the container. The two fours are removed from the container by spectator, and he is surprised, in opening the sealed envelope, to find the two blank cards.