You mustn’t tell a soul.’ One hour after the 157 times tables Powerscourt was being rushed to an emergency meeting at the British Museum. Inspector Kingsley looked as though he hadn’t slept properly for days. He hadn’t yet told Powerscourt the reason for their journey, driven at top speed across the capital by one of the Inspector’s sergeants. ‘Very well, Inspector. You have my silence. Does what you want to say have to do with the Caryatid?’ ‘Not directly, no.’ ‘What do you mean, not directly?’ ‘I’m going to resign, that’s what I mean. I’ve decided.’ ‘What do you mean? Today? Tomorrow? Next week?’ ‘Oh, I’m not going to do anything as drastic as that. Once this case is over I’m going to leave and start afresh. I’m going to write my letter of resignation this evening and hand it in later. I’ve talked it through with the wife.’ ‘Could I ask about the reasons, if they’re not too private?’ ‘You can, of course you can. I feel I’ve failed in this case.