By Gail Pennington
McClatchy-Tribune

A horrific car crash turned Michael Britten’s life upside-down. His wife died. His son died.

Or not.

Britten, a Los Angeles police detective played by the great Jason Isaacs, finds himself living in two realities in NBC’s engrossing new puzzler “Awake.”

“So tell me how this works,” asks his therapist, Dr. Lee (B.D. Wong), in the series opener.

“I don’t know,” Britten tells him. “I close my eyes and open them, just like you.”

But when Michael Britten goes to sleep with his wife, Hannah (Laura Allen), they’re mourning their dead son Rex (Dylan Minnette). When he wakes up, he eats cereal with Rex, a teen who remains deeply shaken by the loss of his mother.

That’s right ­— in one of Britten’s realities, his wife died, but his son survived. In the other, his son died, but his wife survived.

No wonder his police-assigned shrink is puzzled. So is his other, alternate-reality shrink, Dr. Evans (Cherry Jones). Each assumes he’s dreaming half the time — but which half?

“I can assure you this is not a dream,” Evans tells him.

“That’s just what the other shrink said,” he responds.

Back at work, with only his shrinks (and, in one reality, his wife) knowing his secret, Britten isn’t particularly interested in solving his problem.

He is happier this way, he knows, than he would be with one of his loved ones permanently out of his life.

Beyond this big mystery, which gets deliciously more complicated over the course of four episodes sent for preview, “Awake” is also an absorbing police procedural.

With different partners (Steve Harris and Wilmer Valderrama), Britten investigates different cases each week, but clues from one begin to bleed over into the other, something that’s useful but hard to explain.

To keep his two worlds straight, Britten wears a rubber band on his wrist — red for days with his wife, green with his son.

The two worlds are also shot in a slightly different visual style, with different color saturation, so as puzzling as “Awake” is, it’s rarely confusing.

Acting is strong throughout, particularly from the reliable Harris (“The Practice”) and surprisingly intense Valderrama (“That ‘70s Show”).

Creator Kyle Killen, who previously brought us the shockingly short-lived “Lone Star,” is fascinated by dualities.

In “Lone Star,” his protagonist was a swindler living a double life to defraud. “Awake,” though, benefits from a much more sympathetic hero.

Michael Britten doesn’t want to fool anybody, except possibly himself.

He’s a man who is struggling with grief, confusion and the need to move forward in spite of all that.

“Awake” also benefits enormously from the talent of Isaacs, who has been outstanding in everything from PBS “Case Histories” to the “Harry Potter” movies (as evil Lucius Malfoy).

Here, he’s completely believable as a manly man making the most of a situation he doesn’t understand.

Is Michael Britten crazy? Is he dreaming half of his life, and if so, which half?

Or, maybe, are wife, son and even husband all dead, living in some “Lost”-like purgatory?

“Awake” viewers will have all those questions, and will surely enjoy getting the answers.