The Tenth Doctor saves Douglas Henderson from an alien. Taking him aboard the TARDIS, the Doctor reveals Douglas is in fact a bomb designed to disable electronics. The TARDIS is brought on board the ship of a race of green aliens. They are at war with the yellow aliens pursuing Douglas previously. They want Douglas as a weapon for their war. Douglas activates, letting out a pulse that disables both fleets. The Doctor saves Douglas, with enough power to last one human lifetime.