Thorne stumbles across a dastardly killer of young women who has been making their deaths appear to be the result of strokes. The only witness (Sara Lloyd Gregory) just barely survived and is left paralyzed, with no memory of the assault.
Thorne has the unenviable task of trying to get a frozen, unresponsive woman to communicate. Meanwhile it becomes increasingly clear with each new murder that the killer is intimately acquainted with the most monstrous and disturbing case of Thorne's career.
Morrissey starts the mystery looking like a young Liam Neeson. By the time it's over, he appears to have swallowed a hand grenade.
Sleepyhead is further proof that the British do police procedurals better than we do. They're masters at capturing the sheer drudgery and blind serendipity that go into solving crimes. This case grows increasingly layered and complex during its 130 minute unspooling.
You may find yourself confused at times (I admit I was) because Sleepyhead doesn't spoon feed you clues the way American television does. I rather admire that unwillingness to compromise. Really, when was the last time you felt evenly slightly disoriented watching a TV mystery? It's refreshing.
Sleepyhead has a great cast, including Natascha McElhone (Ronin) and Eddie Marsan (Sherlock Holmes). But the real treat is seeing Aidan Gillen in a role so different from the deviously diplomatic Littlefinger in Game of Thrones. Gillen is indelible here as Thorne's wiry friend Phil, the troubled, heavily tattooed coroner.
You can get that same kind of casting frisson tomorrow night when Encore presents Thorne: Scaredycat. The surprise there is seeing Sandra Oh of Grey's Anatomy speaking with a pronounced British accent.
Whether you'll be back for a second installment of Thorne depends on how much you like a challenge.
Contact David Hiltbrand at 215-854-4552 or firstname.lastname@example.org, or follow on Twitter @daveondemand_tv. Read his blog, "Dave on Demand," at www.philly.com/dod.