Spoiler alert: Do not read unless you’ve watched “True Detective” episode 2.07: “Black Maps and Motel Rooms.”

Though it probably wasn’t enough to change the minds of frustrated viewers whose complaints about the second season of “True Detective” prompted HBO’s president of programming to publicly defend the series earlier this week, tonight’s penultimate episode, at the very least, tied up several loose ends.

Unfortunately, the exposition-dump required to get there may have tested the patience of its few remaining fans. Not helping matters, the climactic action sequence was far less riveting than the expertly-staged Vinci massacre scene from three weeks ago.

Having narrowly escaped from the Kubrickian orgy that ended in bloodshed at the climax of the previous episode, tonight’s plot-heavy entry begins with Ani, Paul and Ray holed up in a motel, licking their wounds, both physical and psychological.

Ani’s PTSD is in full swing following her harrowing descent down the rabbit hole. “I’ve been waiting my whole life for that,” she says, referring to killing a security guard who tried to strangle her. “I think I even went looking for it.”

While she and Vera, the missing prostitute they rescued, sleep off the drugs given to them, Paul and Ray comb through the stolen contracts in the first of many long conversations meant to make sense of this season’s labyrinthine plot.

Thankfully for the viewers, though not for Paul, someone texts the former motorcycle cop several indiscreet photos of him and his lover Miguel, interrupting the scene’s barely audible dialogue.

Those secret snapshots are just the first in a series of mysterious, and deadly, repercussions that challenge our exhausted heroes as the nest of vipers they’ve stirred up begin to strike.

Soon enough, everyone’s gone into hiding and corpses are piling up, including State Attorney Davis, whose bullet-ridden body Ray stumbles across when he meets with her to come clean about the botched mission. Unfortunately for him, one of his guns was used for the murder.

As the walls close in, Ani sends her father and sister away to parts unknown, while Paul stashes his fiancée and his harpy mother in a cheap motel room to keep them safe from the violence that’s about to erupt. Considering his mom’s past behavior, why he doesn’t spring for two rooms is perhaps the season’s greatest mystery.

Then there’s Frank, this episode’s surprise MVP. Watching Vince Vaughn’s loquacious mobster literally torch his criminal empire after discovering the full extent of the conspiracy working against him offered a much-needed dose of cathartic humor.

In the episode’s standout scene, Frank confronts Blake, his conniving second-in-command, and exacts cold-blood revenge. Vaughn, whose overwrought dialogue has been one of the main complaints about this season, hits just the right note of menace as he calmly reminisces about the good old days while looming over the fatally gut-shot Blake.

With Ani and Ray now considered fugitives, the two of them have no choice but to hide out together at yet another motel and pore over more info. Eventually, however, they stumble across a name and a face they’ve heard and seen before; Laura … aka Erica Jonson, Caspere’s seemingly innocent office assistant.

And just like that, the final few answers are revealed. It seems as though Laura/Erica was one of two children orphaned in the 1992 jewelry heist that resulted in those mysterious blue diamonds being stolen. Could her older brother Leonard still figure into the story? There’s only one more episode to wrap up this convoluted plotline.

But what’s now perfectly clear is that Caspere’s death was a revenge killing, orchestrated by the child of the two store owners he, Burris, Dixon and Holloway murdered amid the chaos of the L.A. riots. This might even explain the personal nature of Caspere’s mutilation, including the acid to his eyes and the shotgun blast to his testicles.

As far as MacGuffins go, those blue diamonds are no Maltese Falcon. In fact, their presence has arguably been this season’s least interesting detail. So the revelation that they’ve been the catalyst to the entire story is more than a little disappointing.

Having seemingly uncovered Caspere’s murderer, Ani and Ray celebrate by making out in a scene that’s as unconvincing as it is uncomfortable to watch. It’s hard to imagine anyone wanting to see these two damaged characters become romantically involved, and the actors themselves appear less than convinced. Though they’ve displayed decent chemistry at times throughout the season, Farrell and McAdams generate zero heat in this unwelcome plot development.

And that leaves the doomed Paul, who’s been blackmailed into a late night rendezvous that explodes in gunfire deep inside the dimly lit subway tunnels beneath L.A. Sadly, this sub-par shootout plays more like a standard TV action sequence than a memorable sendoff to a character we’ve grown to like.

After singlehandedly dispatching a team of heavily armed mercenaries using his “god warrior” skills, Paul is shot in the back by Lieutenant Burris as he flees from the subway station; a somewhat ignominious end for one of the series’ best characters.

With so few likable characters left on the show, hopefully a similar fate won’t befall Ani and Ray next week.