The Cheltenham Square Murder is a pretty standard Golden Age murder mystery, without major surprises and tending towards being a police procedural, given that the two detectives are both police — and not even Scotland Yard, but local police, albeit one of them displaced from his usual area by a holiday — and the plot follows the step by step by step of their assembly of suspects, witnesses and evidence. There’s even a map!
I’ll admit I jumped ahead to the solution by guessing who seemed most unlikely and who had the absolute best alibi, because that’s how it goes with a lot of the Golden Age novels. It ends up being fun enough, a little puzzle with low stakes for the reader, without great attachment to the innocence or guilt of any particular character. Needless to say, at the end order is restored and justice will be done — and all ends very comfortably like that.
So, not inspiring or surprising, and the writing quality doesn’t elevate it (as I would argue E.C.R. Lorac manages with most of her novels) — but fun enough if you know that’s what you’re getting, which is exactly why I picked it up!