Based on the much loved Inspector Morse series, taken from the novels by Colin Dexter, Endeavour is a prequel, but to describe it as such feels a touch unjust. With a more imaginative title than Young Morse or similar, Endeavour is free to stand on its own merit.

As played by Sean Evans (Ashes to Ashes, The Take), a relative unknown, Endeavour Morse begins the series as an introverted young detective constable, unsure of his place in the world. He’s on the verge of leaving the force, for lack of an intellectual challenge, when called to join the search for missing schoolgirl Rose Tremlett. As with the original series, Endeavour is set in an idealised Oxford of cloistered colleges and leafy suburbs. The setting, lushly filmed, together with Endeavour’s careful pacing, gives the sense of conferring a privilege to viewers, a glimpse into a rarefied world running parallel to ours.
  
In order to remain accessible, Endeavour—which premiered 2 January on ITV1—does risk lapsing into dull, class-bound cliché. Morse has to endure the sniping of duty-bound but slow-witted plods, threatened by the ideas of a ‘college boy’; it also chucks in some police corruption for good measure. Worse, as is too often the case in recent British thrillers,  the intelligentsia are all sneering, cynical and untrustworthy; the working class family of the missing girl flawed, but honest.

Endeavour transcends these potential pitfalls in large part due to restrained writing, and Evans’ performance. He adopts a number of physical tics from the late John Thaw, who played a greyer, and less open Morse in the original series. Without resorting to impersonation, he conveys a thoughtful, fiercely moral but naive character.

Happily, Endeavour soon gets the necessary nostalgia out of the way, introducing trappings of the character familiar to fans early: the love of opera, the red Jaguar, the aversion to blood. It stops short of alienating new viewers with too many winks to the fans, despite a knowing exchange featuring Thaw’s daughter, and cracks on with the plot.

It also introduces another recurring feature of Inspector Morse: his preference for cultured, unattainable women. This time, in the form of hints at a failed romance and a suspect’s comely wife, a former singer, played by Flora Montgomery. There’s a sweet, awkward moment when Morse’s professional manner falls away to reveal a boyish enthusiasm for the music when they first meet. Another of Endeavour’s unexpected pleasures is language.  The inclusion in dialogue of colloquialisms out of common usage like feels authentic, not forced, which makes this more than an episode of Morse in vintage costume.

Endeavour also features some excellent guest turns, most notably from the always good-value Roger Allam, as a superior who fosters Morse’s knack for the job, despite the doubts of his fellow officers, and Patrick Malahide as a cold, sinister politician. 

Even with the hints of menace throughout, as pointed out by a chirpy police pathologist (James Bradshaw), Morse, and Endeavour are both a little squeamish. Both shy away from the grisly or aspects of policing and of death, glossing over fallout among the living. Endeavour treats the events that follow Rose Tremlett’s disappearance as interesting mental exercises – much more murder mystery than crime drama. A flaw, or not, depending on the viewer’s point of view.