Although Oliver Fitzroy performs well as Wellington's research detective, his father police commissioner Fitzroy literally knocks the 'family disgrace' a black eye and forces superintendent Munro to reassign him to field duty, but now under clueless Phelps, until William can requisition him for 'encyclopedic skills'. Phelps is indeed also taking charge of the case of a medicine firm being blackmailed repeatedly with poisoning by use of a rare plant. Scarlett is hired by them but finds a competitor with far greater resources on the case, with a reporter lurking, while William's help is as vital as ever and the knowledgeable Royal Society only helpful when Scarlett poses as socialite candidate-member and flirts with the president. A next, near-fatal poisoning strikes the Indian founding partner's heir, and the motive may be indirect as a bankruptcy might enable a charitable project.
—KGF Vissers