“And her own nephew? Captain Grace?”

“He was actually taking an engineering course at Heidelberg in 1939 but he left on the advice of some of his German friends and returned to England. May I take this opportunity of assuring you that Douglas is not in the pay of Hitler or any of his myrmidons, a belief ardently nursed, I feel sure, by Sub-Inspector Jackson. He enlisted when he got to England, was transferred to a New Zealand unit, and was subsequently pinked in the bottom by the Luftwaffe in Greece. Flossie hauled him in as soon as he was demobilized. He used to work here as a cadet in his school holidays. He’s always been good with his hands. He’d got a small precision lathe and some useful instruments. I pulled him in. It’s Douglas who’s got this bee in his bonnet. He will insist that in some fantastic way his Auntie Flossie’s death is mixed up with our eggbeater, which is what we ambiguously call our magnetic fuse.”

“Why does he think so?”

Fabian did not answer.

“Has he any data—” Alleyn began.

“Look here, sir,” said Fabian abruptly. “I’ve got a notion for your visit. It may not appeal to you. In fact you may dismiss it as the purest tripe, but here it is. You’re full of official information about the whole miserable show, aren’t you? All those files! You know, for example, that any one of us could have left the garden and gone to the shearing shed. You may even have gathered that apart from protracted irritation, which God knows may be sufficient motive, none of us had any reason for killing Flossie. We were a tolerably happy collection of people. Flossie bossed us about but more or less we went our own way.” He paused and added unexpectedly: “Most of us. Very well. It seems to me that, as Flossie was murdered, there was something about Flossie that only one of us knew. Something monstrous. I mean something monstrously out of the character that I, for one, have conceived of as being ‘Flossie Rubrick’ —something murder-worthy. Now that something may not appear in any one of the Flossies that each of us has formed for his or her self, but to a newcomer, an expert, might it not appear in the collective Flossie that emerges from all these units put together? Or am I talking unadulterated bilge?”