You’ve been in a collision. You wake inside the TARDIS. The Doctor introduces you to the person, or thing, you collided with. He’s a strange and magnificent ball of living energy called Volta. Part surly teenager, part bomb, Volta is very unstable. In fact, he’s primed to explode. Big time. Unless he can be returned to his home planet, sharpish. The problem is, a squad of galactic busybodies has other plans for Volta. Bad ones.