It is 1925 and everything is not quite as it should be at Exeter College, Oxford. Undergraduates have been observed behaving very oddly and your diverse set of characters have been asked to investigate discreetly before a major scandal ensues. Is this just a case of youthful high spirits or is there something more sinister behind their conduct?

It is 1944 and the Axis are losing the war. Certain individuals in the German High Command have come to believe that the British have found a way to crack some of their military encryption and are employing unconventional means to stop them. As members of the Bletchley Coven and also staff at Station X - the top secret site where such code-breaking is indeed taking place - you are uniquely placed to stop them and, just maybe, save the whole Allied war effort - starting with renowned mathematician Alan Turing, who you fear is being targeted. Unfortunately, you must contend not just with arcane Nazi threats but also with the scepticism of your own superiors regarding anything that smacks of the supernatural.