At archaeological excavations in 1936, relics from another time were discovered. And, as the Doctor, Amy and Rory discover, from somewhere else. From another planet. But if Enola Porter, an extraordinary traveler, really discovered evidence of the existence of an alien civilization, how could she remain unknown? Why has Rory never heard of her? Besides, why, after traveling with the Doctor for so long, does Amy think that he is from Mars? When the ancient ship is restored, the Doctor finds out that no one and nothing can be trusted. Things that seem extraordinarily real may turn out to be mere fakes and extremely deadly. Who can the Doctor trust if everything around him is not what it seems? And how can he defeat an enemy who mutates at his own will? For the Doctor, Amy, Rory and all humanity, the long-buried secrets of the past are a great threat to the present...