In the late 1950s, Disney contracted with the Stratemeyer Syndicate and Grosset & Dunlap to produce two Hardy Boys TV serials, starring Tim Considine and Tommy Kirk. The first of the serials, The Mystery of the Applegate Treasure, was aired on The Mickey Mouse Club in 1956 during the show's second season. To appeal to the show's audience, the Hardy Boys were portrayed as younger than in the books, seeming to be 11 or 12 years old. The script, written by Jackson Gillis, was based on the first Hardy Boys book, The Tower Treasure, and the serial was aired in 19 episodes of 15 minutes each with production costs of $5,700. The main characters are Tim Considine as Frank Hardy and Tommy Kirk as Joe Hardy.