The Doctor and Fitz are back together at last, but the Doctor is not the man he once was — which is a shame, because Fitz has promised Anji Kapoor that his old friend is Anji's best hope of finding her alien-abducted boyfriend, Dave. Can the Doctor find Dave before the alien contact proves fatal? Who are the secret agents keeping tabs on the rival Space Race teams? Will the Doctor's mysterious blue box finally reveal its purpose? And does the Doctor, now truly a man without a past, have what it takes to stop the Kulan Invasion of Earth...?