`And all the time,' Hadley mused, `suspecting she was being watched, see what the note says: "Be careful. Suspect. Vital." The letter was posted at ten-thirty last night in Mrs Bitton' s district, after Driscoll had paid a short visit that evening. Mrs Bitton had just come back from a walking tour of Cornwall…, and why, in God's name, a walking tour in Cornwall in the worst part of March, unless somebody wanted to get her away from a dangerous infatuation?’
'I'm running on, I suppose. Still, if we assume all this, we must assume it was a dangerous infatuation. For here's a private detective who has been planted in a flat opposite Driscoll for some weeks, even during the time she and her husband were away!… Does that mean anything? And who planted her there? Offhand, of course, the husband.!
'But the name, "Mary"?' suggested General Mason.
`I've heard many more hilariously funny nicknames whatd'yecallem pet names… in my time,' Hadley said, grimly. 'And the handwriting's undoubtedly disguised. Even if it were stolen, it couldn't be used as evidence against her. She's a clever woman.
`Do you see the deep waters we're in now? Come along, Mr Rampole,' he prompted, turning so suddenly that the American jumped; `do you see how it mixes everything up?'
Rampole hesitated. `I can see plenty of difficulties,' he returned. `That letter would have been delivered fairly early this morning. Now we've been assuming all along that the reason why Driscoll telephoned Mr Dalrye had something to do with the hat-thief and his pursuit of the hat-thief. But Driscoll never actually said it did. Dalrye asked him jokingly, if I remember it right, whether he was afraid of his hat being stolen. But all Driscoll actually answered was, "It's not my hat I'm afraid of; it's my head." Dalrye thought it referred to the hat affair; but did it?'
He looked bewilderedly at the chief inspector.
`I don't know,' snapped Hadley. `But he makes that appointment with Dalrye for one o'clock. The appointment in the letter is for one-thirty. He has received the letter that morning; it's scared him, and he wants Dalrye's help. Then some other person sends Dalrye on a wild-goose chase to Driscoll's flat. Driscoll arrived here, in a bad state. He is seen by Parker looking out o f the window, and later somebody touches him on the arm by Traitors' Gate.
`What went on in the merry-go-round composed of Driscoll, Mrs Bitton, Larkin, and a possible fourth party? Was it some sort of crime passionel? And if it was, can anybody on this' side of sanity inform me why Driscoll's body should be found wearing Sir William's stolen top-hat? It's the hat thief angle that's mad and impossible.'
There was a pause. Dr Fell took!he pipe out of his mouth and spoke rather plaintively.