In the third episode of Widow's Bay, the historical journey of the town unfolds before the viewers' eyes as a video is shown at the Historical Society, crediting Richard Warren as the pioneering Mayor of Widow's Bay. As Gerrie continues her tour, tourists, despite the arduous walk, listen intently.
Meanwhile, Tom experiences a surge of pride as he observes the influx of tourists. On his way to work, he encounters Marissa, a lost tourist whose street signs have been altered as a prank. He offers her a ride and mentions the inaugural swimming event and sunset cocktails. Marissa reveals that she's visiting for a bachelorette party and is staying at the inn with her friends, who are keen to explore Barnabus Cavern that evening. She flirts with Tom and subtly invites him to join them.
At the office, Dale reports that some local businesses are reluctant to pay the city sales tax. He seeks Tom's advice, but his boss is preoccupied with thoughts of Marissa. Instead, he tasks them with promoting the sunset cocktails event. Patricia wonders what has prompted this behavior, and Tom shares his encounter with Marissa, only to receive cross expressions from his colleagues, particularly Patricia, who questions if his interest in Marissa is due to her looks.
That evening, Tom prepares to meet Marissa, lying to Evan that he's going out to meet with colleagues. He reminds Evan of his grounding and asks if he's behind the prank with the street signs. Evan denies the accusation, and Tom leaves. Unfortunately, Marissa and her friends never visit Barnabus Cavern. Tired of waiting, Tom returns home. On his way, he spots an old lady and offers to help. She ignores him but suddenly starts running towards his car.
As Tom looks at her eerie face, he turns his car and drives off. He stops to determine where the lady has gone. She creeps up behind him and scratches his hand, adding an unexpected and thrilling twist to the evening.
Scared out of his wits, Tom made a beeline for Dr. Morgan's clinic to treat his wound and called the sheriff, Bechir. Tom believed that the woman might have escaped from the mainland's mental hospital. However, Bechir was impatient and refused to take Tom's report seriously.
Meanwhile, Dr. Morgan warned Tom not to participate in the inaugural swim, but Tom insisted that people were eagerly waiting for the mayor to take the first plunge of the summer to prove the water was safe. He returned to the office where Ruth informed him that Marissa had stopped by, leaving a message that she might meet him at the inaugural swim later that day. Rosemary interrupted Tom, telling him that the woman he met was a sea hag, a creature that, according to legend, if scratched, would start tracking its victim. Tom ignored her and left before she could finish the story.
He headed to the inaugural swim event, where residents were already gathered. Dale reported that Patricia had forgotten to mention that they couldn't get electricity at the beach. He tried to reach out to Garret for help with a converter, but Garret was taking his time leaving his house. Tom decided to address the crowd without a microphone, and they cheered him on as he got into the water to swim to the buoy. There, he saw the sea hag again. This time, he swam as fast as he could, but she managed to scratch his leg.
After the terrifying swim moment, Tom headed to Wyck house to ask about the legend of the sea hag. Wyck was surprised to see him and gladly explained the story. According to the legend, the sea hag tracks her victims using the blood and skin acquired from her scratches. She later finds them and kills them by sitting on their faces.
Tom, being inherently skeptical, gets up to leave. Wyck enquires from him when exactly the sea hag first claimed him. He advises Tom to lock himself in a chest for 72 hours until his wounds heal. He asserts that by nightfall, Tom will feel exhausted and unable to move. That's when the sea hag will get him, when he's too weak to defend himself.
Tom heads home, and Evan uses Marissa's call as a distraction from the fact that he has friends over, despite being grounded. Evan then manipulates his dad into allowing him to have a sleepover at a friend's place so that Tom can enjoy his date with Marissa at the Driftwood.
Tom and Marissa's date goes smoothly, albeit with Kathy's poor waiting skills. Tom opens up about his deceased wife and how he and Evan have been coping. Marissa, obviously feeling sorry for him, consoles him. She suggests going back to Tom's house, but he turns her down.
In town, the priest gets lost in the forest. He comes across an old well and listens to strange noises coming from it. He runs into Evan and his friends drinking and tells them that there's evil in the town. They ignore him and continue partying.
Meanwhile, Wyck leaves Tom a voice message on his house landline, warning him that the sea hag will try every means necessary to get inside his house. Tom starts getting ready for bed. Marissa drops by his house, and he refuses to open the door for her. He questions how she found out his home address and why she's insisting that he let her in. He believes she's the sea hag and chases her away. She gets into a taxi with her friends and leaves.
Spooked, Tom grabs a bat, reinforces the door with a chair, and sits watching the door. The sea hag comes to him in the form of his dead wife while he's sleeping. She gives him a drink, and suddenly she takes her true form. He's unable to fight her off as she moves to sit on his face. Thankfully, he pushes the reclining lever, and she flies off the chair. He crawls his way into the bathtub, but she finds him. Just when she's about to pounce on him, Wyck arrives and shoots her. She dissolves into sea muck. Tom immediately asks Wyck why this strange encounter happened. However, Wyck has no answers either.
The episode ends with Tom getting a voice message from Bryce, the priest. He claims he heard it - we're unsure if he's referring to the church bells tolling. He seems troubled and quickly apologizes before hanging up the call. The scene then cuts to Bechir over the radio, asking for help from all available units, saying he has no idea what's going on.
