Charlie Adams, 45-ish oral surgeon, is a narrator/amateur-sleuth very much in the early Dick Francis manner--tangling with ruthless villains, pluckily surviving assorted ordeals, providing informative atmosphere (sailing, fishing, Cape Cod) along the way. And Charlie's adventures begin when, early one morning, suffering from mid-life insomnia at his Cape Cod vacation cottage, he spots (and photographs) a fishing boat called Penelope, seemingly stranded out on Billingsgate Shoal. Curious, he asks young neighbor Allan to swim out and take a look. So, when Allan later turns up drowned in the harbor, Charlie feels responsible--and, emerging from his angst, starts investigating. The boat seems impossible to trace, its official owner a fictional creation. Charlie suspects a connection to the recent disappearance-at-sea of businessman/treasure-hunter Walter Kincaid--especially when a photo of a Kincaid associate (who supposedly drowned in Alaska) matches up with the photo of the mysterious fishing-boa skipper! And the largely nautical trail, strewn with corpses and assassins, leads from Gloucester to Plymouth to a truck-farm (an Ireland arms-smuggling hideout)--while Charlie is near-drowned, locked in a warehouse, savagely kicked, stranded on a factory roof, and driven to grisly murder. A bit too slow and slack for maximum thrills, perhaps, with a somewhat overwrought plot; but Charlie is a likable, ironic sort (with engaging wife and sons), and the evocative treatment of the Cape Cod scene offers a nice balance to the more visceral derring-do sequences.