He's on a leave of absence from the force and laying low in a rundown cottage on the edge of England. But a visit from his old colleagues at the Met soon bring shocking news that draws him back to London.
Meanwhile, there's a gruesome serial killer on the loose whose twisted logic has the cops baffled.
This murdering mastermind is outsmarting them at ever step – and Luther's the only person who can take them down. Can he catch the killer before it's too late?
Luther, BBC1, 9pm
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