Supt. Richard Jury, down in the village of Long Piddleton again, visiting chum Melrose Plant, finds his vacation suddenly interrupted--when a bloody corpse falls out of a secretaire in Marshall Trueblood's posh antique shop. The secretaire, it turns out, was just purchased from Lady Summerston, aged grande dame of the Watermeadows estate; and the body is that of Simon Lean--the fortune-hunting, philandering, caddishly charming husband of Lady Summerston's reclusive granddaughter Hannah. At first the primary suspects are the dead man's local mistresses, along with his neglected wife (who claims to have been ready for divorce--and thus unmotivated). But Jury then goes to London, on the trail of Simon's lowdown Limehouse-district mistress, and runs directly into another homicide; the murder of ambitious street-girl Sadie Diver. . .who was indeed Simon's girlfriend. . .and who bears a strange resemblance to Simon's wife Hannah! Obviously, the two killings are linked, but exactly how? The possibilities are endless--because Sadie's body can't be definitely identified, not even by her devoted little brother (whom Jury touchingly takes under his wing). So, while considering all the identity-switch alternatives, Jury plays cat-and-mouse interrogation games with Hannah Lean--who is either an imposter or a murderer. . .or both. "Ambiguous to the end," this ninth Jury episode is an unabashed mixture--part sentimental comedy, part trick-whodunit (very reminiscent of double-twist Christie), with a touch of dark Brat Farrar-ish psychological suspense. But, even if oddly paced and blandly padded (sidekick Melrose Plant has never seemed so extraneous), this is steadily absorbing and stylishly crafty in its varied moods: further evidence (with last year's I Am the Only Running Footman) that Grimes intends to avoid the formula foolishness that once threatened to submerge her impressive career.