Annika picks up not quite two weeks after last week's disastrous open-mic experience. Honestly, I'm not sure what Annika thinks she's doing. The obvious answer is opening a deck chair on the roof to enjoy an ice cream, but it's all gone wrong. It's a pretty blatant metaphor for her failed attempt at telling Michael about having an extra daughter, but at least he's come back, like a pup who couldn't stay away. She's relieved — apparently, she thought he'd quit altogether, which was the opposite of what she intended. She worried he'd take the girl from her, and he hadn't even told Astrid.
Annika: I thought only Bond villains had aquariums in the basement.
This week's victim is high profile, a billionaire named Fabian Hyde, a green tech entrepreneur who drowned in his shark tank. The name should have been a tip-off of the week's book even before Annika mentions Robert Louis Stevenson, but if you don't remember your seventh-grade reading, it's The Strange Case of Dr. Jekyll and Mr. Hyde. Honestly, the book is less about the case than it is about her and Michael, but that's been a running theme all season, so no surprise. Annika would divide the team up and spend the day with Blair while Michael hung with Tyrone if she were an intelligent woman. No one said Annika was smart.
Blair and Tyrone question the house manager, January Deacon (Shereen Cutkelvin), who says Hyde wasn't even supposed to be in the city but out in Dundee. The security system was also out, and the backup system didn't kick in. However, earlier in the day, the camera did catch Greg Connolly (Russ Bain), someone Hyde screwed over in a business deal, showing up to the house and the two getting into an argument.
Annika and Michael head to visit the next of kin, who learned of Fabian's death about ten minutes before the press did, and are holed up in their mansion. Katherine Hyde (Jessica Hardwick), Fabian's daughter, lives the life of the ultra-wealthy, volunteering at women's shelters and so on; she claims her father and mother divorced when she was little, and he never remarried. Katherine's daughter, Grace (Layla Cook), who is deaf, is following in Grandad's footsteps; Grace's BFF, Dylan McQuade (Tiger Mitchell), lives with them, he works at the chippy around the corner.
Poor Annika has to do press for this since it's a high-profile victim; why Oban thinks this is a good idea is beyond me. (Even Annika knows it's a terrible idea.) Michael can't watch, so he, Blair, and Tyrone chase their only lead, the guy at the door, who, it turns out, had to foreclose on his business, Doxon Holdings Recycling, due to Fabian. They head over to talk to Connelly, arriving just in time to rescue him from a mob of his own angry, laid-off workers. He swears Fabian was alive when he left.
With the press dealt with, Annika goes to hang out in a graveyard and admits to herself that part of her wanted this since she was the one who returned to the scene of the rime, this city, this unit, knowing full well he worked here. She tries to imagine the version of herself that told him 16 years ago she was pregnant, who didn't run. It's not a very believable version, to be fair. But she makes one quite clear: Knowing is Morgan's choice, and that boundary is sacred. However, we'll see how long that lasts as Morgan is plotting to host Femi's birthday party.
Hyde, it turns out, was drowned after a blow to the head; it seems someone dropped a clock on him in the tank. There are many people with motives; Hyde was the landlord of half the village and wanted them out so he could use the land for fracking. (That's not very green!) The McQuades at the chippy spearheaded the move to stop him. Dylan is clearly in love with Grace but says he never pressured her into lobbying for his family's business. He did try to lobby her mother and failed, calling Katherine a coward. Dylan's parents have an alibi, they were at the chippy that night, and besides, Fabian's death doesn't necessarily mean the fracking stuff won't happen now.
However, an odd twist comes up, as Annika's press conference, which we did not see, suddenly shows up on everyone's phones, deepfaked to say some super impolitic stuff. It's a strange twist since, up until then, no one involved seemed very tech-savvy. Heck, Annika and Michael were leaving a hardware store where the owner, Ross Kincaid (Andrew Still), Grace's father, whom Fabian did not approve of and tried to cut off from both his daughter and granddaughter, was admitting he had punched the guy a few weeks back.
The only real tech-forward suspect is January, with her security-savvy. Tyrone digs up that Fabian's been making erratic large payments to her for years, including one made online during his video argument with Connelly. But that turns out to be a red herring, a wacko hacker in the basement of a skating rink, Senga MacAuley (Seylan Baxter), who has been manipulating Fabian's online personage for funsies. At least Morgan thinks Annika being deepfaked is the height of cool? Annika will take what she can get anyway.
With the nonsense out of the way, it's time to actually solve the case, and the obvious suspect is obvious, especially once Blair finds a vibrant piece of hatemail that arrived the day of the murder, and Annika recognizes the handwriting. It's Katherine's, and though she tries to pretend it isn't her, Grace is there to call her out at every turn, from her trying to blame Dylan's mom to her sneaking out the night of the murder (Katherine claims it was to see her mother who wanted money) to her spinelessness for fear of losing her easy lifestyle.
As for January, it turns out she was making the payments to herself, which explains why some of the payments were made when he was busy. But she claims that she was just balancing the scales, the same as his family was doing. It's that that clicks it in Annika's head. It's not Katherine. It was Grace. She'd been called over there, and Faian threatened her, telling her to dump Dylan or she'd be cut off... and then he turned his back and kept talking, and she couldn't read his lips. Frustrated, she threw the clock, which hit him by accident. He fell into the water, and she ran. Dylan's been protecting her since.
With the case resolved, Tyrone's promotion is in, and he's going to be heading to a new post to take up the DCI position. Annika gives him black licorice to weird his new teammates with and tells him to remember to tell bad jokes. Then she gets a lift back home from Michael, as Morgan, Femi, and her partiers took the boat out joyriding, and she forgot to drop the anchor when they got back. (Oops.) The two paddleboat out to rescue it and stop halfway to finally argue it out. It's a good argument. And now that they're on the same page, Annika takes Morgan home, points out that she committed a felony by stealing a police boat, and grounds her. Fair, honestly.