Early-retired Boston PD detective Jeff Jackson is approached by young waitress Katie Leonard, seeking help with unspecified illegal business, so tells her to deal with it, preferably coming clean to Martha's Vineyard police chief Madieras, but she chickens out. On date walk with chief's daughter and local pathologist Dr. Zee, having caught his fish catch for her, Jeff finds her abandoned scooter and backpack, she Katie's corpse, autopsy-diagnosed poisoned with a local plant, as turns out mixed into her self-brewed daily "kombucha" tea. Her ex-con former boyfriend Glen Eads, with a long record, goes missing after an interview but is later found shot dead at home. The case keeps linking with $100,000 Zee found erroneously on her account at the local bank, which is run by Lauren Cabot, who inherited it alone, her brother Noah only a restaurant, where Katie worked. The money came from a bogus company, with a surprising fake contact person, to launder gambling profits, traced to another fake identity entrepreneur. Meanwhile Jesse gets ever more suspicious about his former Boston PD partner Andy Lau, why seems to counter his involvement in their old case which went bad, but is take over by the FBI after they manage to arrest armed fiend Keith McDonough the hard way.—KGF Vissers