I’ve never seen “Grey’s Anatomy.” Not one episode. Not even a small part of one. So I never got caught up in the fuss over actor Patrick Dempsey, who gained fame as TV's favorite neurosurgeon, Derek "McDreamy" Shepherd.

Because of “The Truth About the Harry Quebert Affair,” a 10-part series being shown on Amazon Prime, Dempsey is likely to be re-nicknamed "McBoring." Based on a very successful (and, apparently, much-acclaimed) novel by Joel Dicker, this bloated collection of cliches and complications is another example of what streaming has wrought.

A few years ago it was announced the book would be turned into a movie directed by Ron Howard. That makes sense, but a 10-part series? It may also be significant that a knee-jerk assumption made by a Google computer suggested "Harry Quebert" was a Netflix presentation. Perhaps it was headed that way until someone at Netflix screened the show and said, "Let Amazon have it."

With opening and closing credits, and unusually drawn-out “Previously on . . . ” introductions, “The Truth About the Harry Quebert Affair” really doesn’t run 10 hours; closer to eight and a half, still about six hours and 30 minutes too long.

The British have a better way of handling things, though their series aren’t nearly as entertaining as they once were. They would have done “Harry Quebert” in three 45-minute episodes, and probably would have done a better job of casting.

It’s weird, but just when I was thinking casting directors seldom make mistakes and that you hardly ever see really terrible acting performances any more, along comes this series to disprove both theories.

Dempsey plays a famous writer and college professor, who has a gorgeous ocean-front mansion in fictitious Sommerdale, Maine. (The filming actually was done in Canada.) The story bounces between 1975, before he became successful, and 2005, when the body of a 15-year-old girl, missing for 30 years, is discovered on his property, and he is accused of her murder.

Dempsey, now 53 years old, was, say, 51 or 52 when this thing was filmed, but he is supposed to be either 35 or 65 in the various scenes, though he always looks his real age. Dempsey is blessed with a wild mop of hair, well-tended and apparently real. To affect the age change, powder was sprinkled in his hair, though he could get rid of the white with a few strokes of a brush.

Throughout the series, Dempsey is so sluggish that he could be on life support. Perhaps he was bored by having to say such lines as, “It’s like I’m in a nightmare, and I can’t wake up.” That’s a fair sample of the dialogue, perhaps the corniest since Erich Segal’s “Love Story.”

When he was 35 years old, Harry Quebert had written only one book, and he paid to have it published. Yet when he shows up to spend the summer in a rented home, one he really can't afford, some folks in Maine think he’s a famous author. He becomes infatuated with a 15-year-old waitress, played by Kristine Froseth, who was over 20 when this series was filmed. However, she looks 15, though she reminded me too much of the teenaged Taylor Swift, which I found distracting. I also found her character extremely obnoxious, which caused me to think, that at 35, Harry Quebert was socially retarded. Otherwise, he would have avoided a girl so unstable and needy, with a serious problem some viewers will guess before it's finally revealed. Some may regard Quebert as a pedophile, though it's not quite that simple. It's more like he's not a fully-formed character, one who slept through his first 35 years, then three months later went back to bed.

Dempsey does a poor job of making his character believable, and I'm not going to read the book to see if the fault really lies with the book's author. Quebert may be one of the characters who can exist only on the printed page, or it may be too much of his background was left out of the television script.

Anyway, helping Quebert in his time of trouble is a young writer named Marcus Goldman (Ben Schnetzer), who finally gets to the truth with the aid of a police detective (Damon Wayans Jr.). In a way, they are the main characters, neither is particularly interesting, nor are the actors who portray them.

If it weren’t for my own weakness in wanting to see how stories end, I wouldn’t have stayed with “Harry Quebert.” Well, actually, I didn’t. I fell asleep during episode five, and when I woke decided to skip episodes six through nine and go directly to the finale. I don’t think I missed anything, because, as I said, this series has unusually long “Previously on . . . ” introductions, which filled me in on what I had missed during those four episodes.

Part of the reason I watched in the first place was to see Wayne Knight, best remembered as Newman in “Seinfeld.” He plays Quebert’s lawyer, and may be the best thing in this mess.

I also wanted to see Kurt Fuller, whom I loved as the wacky coroner in “Psych.” He’s grimly serious here as the sheriff or police chief, and I was disappointed by his performance, which jumped out because he seemed to be the only actor trying to speak with a New England accent. (Not even Dempsey sounded like a New Englander, and he was born in Maine, which may be why he was attracted to this project.)

I was looking forward to seeing Colm Feore, who usually is excellent as sinister or slimy characters, but he, too, had a bad time trying to make mysteriously rich and powerful Elijah Stern even remotely interesting. Feore looked especially ridiculous in scenes where he was 30 years younger.

Canadian actor Joshua Close plays a key character. Stern’s one-time chauffeur, the disfigured Luther Caleb, but down the homestretch Caleb becomes almost comical.

Virginia Madsen, who, at 57, is making the transition from siren to colorful character actor, goes over the top as Tamara Quinn, a cafe owner who tries to arrange a match between her prom queen daughter, Jenny, and Quebert. However, her problem, I believe, is the way her role was written.

Jenny Quinn, in the 1975 scenes, is played by Tessa Mossey, who is much more appealing than the 15-year-old object of Quebert’s infatuation.

However, the 2005 version of Jenny is played by Victoria Clark, who may be a Tony Award winner, but she botches this assignment, as does Matt Frewer, who plays the minister-father of the 15-year-old murder victim, Nola Kellergan. Frewer’s role is tailor-made for Keith Carradine, who was in his early 30s when he staked out a claim as the best choice to play menacing crazy guys with his portrayal of Foxy Funderburke in 1983’s “Chiefs,” a series which covered more territory than “Harry Quebert,” and did it in less than half the time.

While I skipped four episodes, what I saw in “The Truth About the Harry Quebert Affair” — when I wasn’t dozing off — were enough trite and ridiculous twists to fill about five stories (including sequels to "Psycho" and "The Sixth Sense"). I had to see how it ended, but that only convinced me I shouldn’t have started watching in the first place.