A rather ordinary magician, called Morton the Affordable, is entertaining Billy's birthday party - not very successfully - until Old Tom's antics disrupt the party, and Morton's assistant quits. Morton desperately needs a new assistant for his appearance on an important TV show, and he picks Old Tom. This makes Billy jealous and, just before the show, he locks Old Tom in one of the magician's boxes and takes his place as Morton's assistant. The performance starts badly, until Old Tom escapes from the box and turns the magic act into comic mayhem. The audience is so amused that Morton becomes a big success and discovers the art of showmanship from Old Tom.