Doctor Who - The 4th Doctor Adventures, Series 1, 5: Trail of the White Worm (Unabridged)
Description of book
When the Doctor and Leela arrive in Derbyshire and get caught up in the hunt for a missing girl, they soon discover that the legend of the White Worm is very much alive, even in 1979. And it seems that the Doctor isn't the only Time Lord on the trail...