worlds best magic trick

the card with a different back was from the beginning the 5 of clubs . it was placed on the bottom of the deck and when the spectator chose a card this card was put on top of the chosen card duing the shuffle . after tht the deck was spread out and u squared up the part with the different back card under which ws the spectator's card .u then did a double lift.after tht was a card force and the card u froced was placed in the bottom of the deck. and this is the trick ! i cracked the theory !