Reading progress update: I've read 34%.

Reeves threw his cigarette away and a few seconds later lighted another match. As he bent over the flame his face was brilliantly lighted, and then he lifted his head and waved the match in the air. Instantly, like some fantastic illusion, another face appeared, some twelve inches above Reeves’, and Mallaig suddenly shouted, as though his strung-up nerves impelled him to give voice. “There’s the third chap… look,” but even as he spoke the match went out and there was a dull thud and a heavy fall. Mallaig jumped up, dropped his torch, fumbled for it and at last turned it on. In the beam of light a man could be seen astride the bridge rail and another lay on the ground. Mallaig sprang forward, but Macdonald’s voice came out of the darkness:
“Steady on, laddie. It’s only a reconstruction you know.”
Mallaig halted with a rather uncertain laugh.
“That was pretty grim, you know. It was exactly what happened last night—except the faces were different. The third chap—he was the same in a way—dark coat and cap—but his face wasn’t like the one I saw last night. What’s so amazing was the way you could see just in the light of one match.”
Yup. This is my last E.C.R. Lorac.
This story focuses on repetitive plodding police work (not my favourite kind of mystery) and inane conversations between characters who lack individuality and ... character.