Collection of episodes from the CGI-animated show for children featuring the vocal talents of David Tennant and Sophie Aldred. Tom Powers (voice of Aldred) seems like an average eight-year-old boy. However, Tom has made an incredible discovery. In the woodland near his house is a special tree that houses Treetopolis, a city inside a tree trunk that he is able to access as a miniature version of himself and interact with the weird and wonderful small creatures of the forest. These include Twigs (Tennant), an acorn sprite, and Zigzoo (Tim Whitnall) the frog.