The magician removes the second to bottom card of the deck, but to the spectator it appears as though the magician took the bottom card.
How It's Done
Hold the deck face down with your right hand, palm on top of the deck, thumb wrapped around the left edge, pinky against the back edge, and other three fingers on the right edge. With your ring finger, slide the bottom card back slightly (inch or so), this should be invisible to the spectator since the deck is face down. Slide your left hand along the bottom of the deck to take out a card, grab the card behind the real bottom card which has been pushed back. With your right pinky, push the bottom card back into place.