This case strays from what I think of as the usual Silver format, in that private enquiry agent Maud Silver isn't brought in during the 2nd or 3rd chapter by one of the sympathetic young lovers who generally turn up in her cases. Instead, she appears after a few chapters of character development spelling out quite clearly just how many people - both would-be lovers and *their* discarded partners - have a motive to kill Tanis Lyle, and Maudie's already engaged in a separate case - a matter of petty thefts from Tanis' wealthy guardian Agnes, who then extends the engagement to cover the murder investigation. (Agnes and her cousin Lucy are old acquaintances of Maud's school days, although they were never close, so she's actually staying with the client rather than a separate old school chum for once.) However, in this instance the flexing of the bonds of the Silver format does no harm; a very pleasant read as either a novel or a puzzle, if you like mysteries spiced with other human problems.
As in a later case, _Through the Wall_, at least two potential murder victims bear a strong enough likeness that when one is killed at night while wearing some of the other's clothing, there's some question as to which was the intended victim. Another similarity is that one is the (apparently) morally worthy heiress, the other a femme fatale, although in a much more drastic contrast than in the later book, where the femme fatale is a (somewhat) more sympathetic character. Motive won't help sort this one out - anybody who didn't have a motive to kill Tanis Lyle did have a motive to kill Laura Fane, and vice versa.
Laura Fane, as the sole surviving member of the senior branch of the family, holds title to the family estate - the Priory - but the next branch of the family has leased it for many years, since they had the money to keep it up, so cousin Agnes has lived there all her life. Jilted by Laura's father, then partly paralyzed by a riding accident, she's devoted herself to 3 things: nursing her grudge against Laura's long-dead parents, maintaining the Priory, and raising her orphaned young cousin Tanis Lyle. Agnes wants to buy the Priory outright, and to persuade Tanis (via her control of the pursestrings) to settle down and raise her son (currently parked with her ex's family), but Tanis prefers proving in wartime London that the enemy isn't the only destroyer of good men - or relationships.
Laura, on the other hand, while bearing a physical likeness to Tanis, is leavened with the milk of human kindness rather than a taste for cat-and-mouse games with men - or their partners' jealousy. But when she and one of Tanis' recent discards - a decent sort with a Distinguished Flying Cross, recovering from injuries that grounded him with temporarily messed-up depth perception - begin falling in love, Tanis arranges matters so that "the aunts" will be sure to raise Cain, seeing Laura as "stealing" Tanis' man, just as Laura's father jilted Agnes for another woman. When one of the girls is shot in the middle of the night, which was the intended victim?
Since the Priory is in Ledshire, Randall Marsh - superintendent and Miss Silver's favourite former pupil - is in charge of the official investigation. (He wryly comments that he's the only member of the family who's *not* in the Army - and he's the only male in his generation.)