“The Depths” is episode six of season one of Special Unit 2 and the season finale
On the beach by the lake, a young couple are making out. The girl stops; she’d rather be someplace safe. The boy knows someone with a house nearby. The girl is worried that something bad could happen. In horror movies, something bad always happens to the girl after. Which leads to a discussion on horror movies and other girls who are sleeping around. However, something is watching from the lake. The girl has a glow around her. She suddenly says she can’t move anything. Then the boy is attacked and tossed aside. A creature lifts her up, sucks something out of her then puts her down again.
Kate is on the phone with her mother, talking about her sister, Megan, who’s staying with her and going on a date. Kate says she’ll personally shoot anyone who messes with her sister. She tells her mother she’s joking. Though she is cleaning her gun at the time. Which she hides when Megan enters. Megan asks how she’s dressed. Kate thinks the skirt is really short. Megan says it’s Kate’s. Kate wants Megan to let her date know her sister is a cop. Apparently, his name is Scar. He’s in a band. They negotiate a time for Megan to be back.
At the lake, Sean tells Nick and Kate that the victim is in a kind of coma, but no matter what position she’s turned to, she always turns to stare at the lake. There’s no cerebral cortex activity. Nick asks if this is similar to what happened two years ago. Identical. Three cheerleaders were found in the same state. The male victim is dead.
Back at the precinct, Sean says the DNA is identical to the Link that was caught last time. Kate asked if it escaped. No; Nick says it accidentally died whilst he was questioning it. Identical twins would have the same DNA. Page enters; there are more than two. There were two other incidents last night at the same time, different locations. All young women. The Link is an icthiosapiens, known as sirens or mermaids. They hypnotise their prey then drain their life.
Interviewing the three families reveals no commonalities. Kate is sure there is something. Nick gets a call; there’s something happening at a sorority house that sounds like the Link. A clearly not bright pizza delivery guy is delivering pizzas to the sorority when all the girls start running out.
Nick, Kate and more officers arrive at the scene. They head inside and are told it’s still in there. Nick finds three girls paralysed; Kate finds more and the merman draining one. It runs away and they try and stop it whilst still keeping it alive. The ammunition doesn’t work, but handcuffing it in the kitchen and hitting it with a frying pan does.
Sean says this victim is the same as the others; alive but nothing inside. The victims were temporarily paralysed, but only one was drained. Nick thinks they should speak to the girls. He and Kate do, and claim it was someone dressing up in a costume. The alternative is that it was some kind of monster, and they know that’s not possible. The girls wouldn’t want people to think they’re different, would they?
They assume the perpetrator gave their friends some kind of drug. So, did the victims have anything in common. The girls have been acting like stereotypical airheads, and eventually come up with something. None of the victims had ever really had boyfriends.
Outside, Nick and Kate discuss that the victims were all virgins. And the girl at the beginning was worried because girls in horror movies always die after they lose that. Kate tells him it’s not unbelievable that they exist. Yes, but at college?
The Links have a communal hive mind and need the energy of others to function. They need to lure one out. Using someone with very specialised qualities. And a Link, because using a civilian would be wrong. And will they be able to restore the girls?