Flower-and-plant expert Celia Grant (The Mantrap Garden, etc.) goes on an English bus tour of Italian gardens--and gets all caught up, as witness/sleuth and damsel. in-distress, in an elaborate scheme involving impersonation, kidnapping, art-theft, terrorism, and murder. The rather muddled mayhem begins when Celia recognizes a supposedly rich South African couple on the tour, the Hansons, as the Vincents, a pair of third-rate actors she once met. Why are the Vincents traveling under false pretenses? Is some criminal scam afoot? So it seems: Celia herself, who Knows Too Much, has a brash or two with nastiness. Then, when the tour visits a historic private villa-and-garden, there's Violence galore: the ""Hansons"" are kidnapped by masked gunmen; another touring couple is found shot to death; the local police are convinced that some priceless piece of antique statuary has been stolen from the villa and smuggled out of Italy. And Celia, whose advice is rebuffed by the Italian cops, is equally convinced that the scheme's mastermind was someone else on the tour. So, once back in England, she tracks down some of her traveling companions. . .and eventually fingers the cool, ruthless aristocrats behind all the skulduggery. Contrived and implausible plotting, raggedly paced--but Celia herself remains charming, the botanical details (complete with scholarly footnotes) are fetching, and series fans may want to tag along even if this is below-par Sherwood.