The story starts aboard the North Star, an American fishing boat in the Berring Strait. They catch a strange creature in the net - more like Harbinger than the mermaid episode of Charmed . It turns out that some MIBs are also looking for mermaids in the area.
The story switches to a small town on the Alaska coast, on the lake that is used in every Canadian TV show from The 4400 to Once upon A Time . It is the time of the annual Mermaid Festival. Local shopkeeper Miss Hawkins ( Rena Owen ) seems to know more about the town's history than she is letting on.
The protagonist is the wayward son of the Mayor (David Cubitt - Medium ), who would rather work as an environmentalist saving seals than attending the civic functions that finance his hobby. He meets a naked girl ( Eline Powell ) in a way that is more realistic than the idealised version in Splash .
It turns out that the mermaids have superhuman strength, even when they are out of the water. They eat raw meat, and feel entitled to help themselves to clothing and anything else that they find lying around. As a result, we can expect at least one innocent person to be brutally murdered.
The protagonist has gone to sea with his buddies, aboard the North Star. The crew just want their friend back, and to do that they must discover where the MIBs have him. The protagonist wants to save the mermaids, to atone for what his ancestors had to do in order to survive.
Rynn ( Eline Powell ) returns to the town, and steals some clothes. The locals are disgusted at her nudity - presumably because she would have no reason to shave below the waist and thus they might regard her as a bad role model for their children.
The Sheriff investigates last episode's brutal murder. He theorises that the dead man might have been victim of a sexual assault. His female deputy replies Looks like he got what he deserved. Yes, the very definition of victim-blaming! In all fairness she is a police officer in America, and standard operational procedure for cops seems to be automatic escalation to lethal force at any excuse.
The protagonist and his girlfriend are left to babysit Rynn ( Eline Powell ). Despite knowing the fact that she has superhuman strength and a bad temper, they pester her with questions and medical tests. Strangely, she seems attracted to emotionally unavailable men. If only the man in the car had played hard-to-get ...
The Sheriff starts to put the clues together. He has a dead body, and tales of a homeless girl stealing clothes.
The fishermen get a clue to the whereabouts of their missing friend. They get a text purporting to be from him, and trace the number to a nurse's mobile phone. All they have to do is tail her from her home to the secret military base. Yes, it seems the MIB staff do not live in a barracks, but in non-secure houses that are subject to the civilian sheriff's jurisdiction.
The Mayor (David Cubitt - Medium ) wants his son back. His prodigal son, that is. This leads to a confrontation between the brothers.
The good guys stupidly leave Rynn alone, even though they know she has a mind of her own. She ends up at a party, where she drinks beer as if it were water. And speaking of water, the party is in a back yard with a swimming pool in the middle. How long will it be before the mermaid ends up in the pool? Well, the babysitters were in charge of her from breakfast time, but it is night-time before they get to the party!
The mermaid in captivity decides to break out. Naturally, she slaughters everyone who gets in her way.
The kidnapped fisherman also decides to break out of the lab. He teams up with a young black woman who wears a nurse's uniform, and does not seem to speak or understand English very well.
This is set a few months after the previous episode. In all that time, not much seems to have transpired.
The MIBs' plan is to pay the local fishermen to remove all fish from the mermaids' feeding ground. This plan to starve the mermaids out succeeds. Rynn ( Eline Powell ) and her sister return to the town.
The Mayor (David Cubitt - Medium ) gets a couple of employees back at work. One is his prodigal son, who wants to nose around and discover his secrets. The other is the kidnapped fisherman, whom the MIBs have lost interest in.