Luther finds all of DCI Luther's worlds colliding as his co-workers, his enemies, and Alice all turn up to his apartment uninvited, all at the same time.
Alice: I had to be dead. That's how all your best relationships end.
This week's episode does new viewers a huge favor and brings us all up to speed on the character that made Luther the hit show it is, Alice Morgan. One part psychopath, one part brilliant entrepreneur, if one can be considered an entrepreneur in the world of crime, Alice was never supposed to survive beyond the show's first season. But she was so popular, they brought her back over and over again. The show did try to skip having her in the two-part Season 4, but that was an utter failure, and so for Season 5, Alice is here again. Moreover, the show, which has slowly softened her into Luther's girlfriend/partner/soul mate has decided that audiences really should be reminded both of what she's capable of, as well as fill everyone in on where she was last season.
The answer, by the way, is working for George Cornelius on a diamond deal, one he double-crossed her on. (Is this is the same diamond stuff from Season 4? One assumes so.) She almost managed to keep them for herself, but a car crash rendered them imperceptible from windshield glass. (Welp.) After murdering her way out of the situation, Alice faked her own death and disappeared for a while. Now she's back, hell-bent on revenge on Cornelius, and popping by Luther's for a place to recuperate from the bullet hole in her side, and maybe grab a cuppa tea.
Those plans, by the way, include George's son. Yes, she's the one who kidnapped Junior, which explains why Cornelius is so convinced that Luther is involved. That's not good at all since Luther and Benny did involve themselves last week. Cornelius is never going to believe Luther wasn't a part of this from the getgo, especially since, as viewers know from last week he and his gang are on the way to Luther's house right now.
However, Luther gets a reprieve from one calamity in the form of another. As viewers also saw last week, Halliday was not satisfied by the answer thrown to the police force by the psycho psychiatrist Vivien Lake and believes the dead killer they have on the slab is really a victim. She and Schenk also decided to go over and check in on Luther (who is not answering his phone), and maybe further discuss things. The good news is that Schenk and Halliday reach Luther's house first, causing Cornelius and company to wait in the car for their turn when they realize who is heading for Luther's front door as they pull up. The bad news is Luther has a serial killer thief who has currently kidnapped a gangster's kid with a bullet wound hiding in his bedroom when his boss and his partner arrive. Awkward.
Schenk hears thuds upstairs and decides to take a gander. He finds the blood from the bullet clean up and grabs one of the gauzes for testing. He almost walks in on Alice too, but, as luck would have it, does not actually enter the room. Poor Halliday is excited and happy that both her bosses are agreeing she's onto something, utterly unaware both are agreeing as a way to cover up the cat and mouse game over Alice to each other. Luther does listen enough to hit upon what viewers know will be a grand notion, paying a visit to the husband to see how Lake responds. Both agree this is the next angle of attack and head home.
With the coppers out of the house, Cornelius and company head inside. Alice was at least expecting this visit, and Luther already has an escape hatch (a literal hatch in the ceiling to the roof). Cornelius gets his proof Alice has been there, but his quarries escape, heading to her parent's old house, where she's holding Junior. Cornelius attempts to deal with Luther to get to Alice through him, but Luther offers up money instead. He shouldn't have bothered, because Cornelius isn't going to agree to play like that.
That's the problem with trusting psychopaths and gangsters. It's also an issue for Benny, who was on his way in to check the blood sample from Luther's apartment for Schenk and got grabbed by Cornelius. And it's going to be a big problem for everyone. Faced with Luther's refusal to start dating again, Alice has chosen Option 2, and taken out poor Junior right under everyone's noses. George is going to kill a lot of people for this.
Just in case the slow ones in the back weren't sure Halliday was right, there are a few scenes spent with Vivian and her husband, who we learn is named Jeremy, and is a heart surgeon. He's also totally insane and has been since the two of them married, with moments reminiscing over him nearly killing someone on a long-ago vacation to Milan, and his joking about the murder on the bus just an episode ago. Vivian is indulgent, but also stern. "Play safe." He doesn't seem to be, though, creepily stalking women and making his patients super uncomfortable. Vivian is right, her husband is losing his impulse control, to the point where he's getting off in surgery.
That's terrible news for Halliday, now mostly working alone since Luther is super distracted. Luther does join her on the trip to visit Jeremy Lake, who claims to have known nothing about Houser until his death the night before and then describes with pinpoint accuracy some of his traits, including the needles in the testicles that Halliday learned out from autopsy only a few hours earlier. But his tendency to snatch women and take them home to his wife seems like a good reason for Halliday to start using the buddy system, and soon.