Playing a traitor was not as easy as it looked, especially when the other two insisted on tailing me as I wandered around the building. We spent so much time apart from the others that when I asked a prominent faithful if she would like to join forces to share notes, she refused.

Instead I was forced to watch old friends work their way through an ancient ledger of the University of Birmingham Ballroom Dancing Society, hunting for their names in attendance lists from the early 1980s. Such records, if found, would supposedly prove that they were faithful.