‘Why are you here? I mean – who are you, exactly?’ An archaeological dig in 1936 unearths relics of another time... And – as the Doctor, Amy and Rory realise – another place. Another planet. But if Enola Porter, noted adventuress, has really found evidence of an alien civilisation, how come she isn’t famous? Why has Rory never heard of her? Added to that, since Amy’s been travelling with him for a while now, why does she now think the Doctor is from Mars?