Nicole and Dave are on the pier when Dave proposes. Nicole delightedly agrees to marry him. The ring doesn't fit, so Dave puts it in his pocket. The stalker nudges into him and takes it. Dave chases them, but loses them.
At the TAU the team interviews both of their exes after they believe they have a stalker. Both ex's seem to not hold grudges about the past.
Celebrating their engagement at a party on the beach, Dave goes off to buy more beer, but is stopped in an under pass and set on fire by the stalker. He manages to escape, but burns to death in front of Nicole.
A distraught Nicole clears out her lifeguard tower and hears a noise under the pier. Her ex goes to investigate, but he is attacked. Nicole wakes him up. he says he was hit from behind. Jack challenges this.
Nicole says a red truck has been following her. It turns out the truck belongs of the parent of a child who died when Nicole was on duty.
The woman says she wants Nicole to be unhappy.
Nicole goes to the bedroom to get ready for bed and someone scares her. Turns out, someone has been sleeping under the house. She goes to stay with Zoe, but the team realizes Zoe is the stalker because Nicole saved her.
Zoe asks Nicole to marry her. Nicole declines and realizes Zoe is the stalker. Zoe tries to make her jump off the pier with her, but Beth and Jack arrive and save the day.