Doctor Who: Warzone / Conversion (258)

Warzone by Chris Chapman
At Warzone, competitors gather from across the galaxy to test the limits of their endurance and achieve their personal best. So, when the TARDIS materialises in the middle of a racetrack, the Doctor and his friends must literally run for their lives.

Conversion by Guy Adams
On the fringes of the galaxy, techno-pirates and research medics fight for the secrets of advanced extra-terrestrial technology. For the Doctor, however, a more personal battle awaits as he confronts his own guilt and the creatures that killed a friend: the Cybermen.