Brody's at home engrossed in a book about sharks. His wife startles him. He just can't believe how little people know about sharks.
She tries to help him relax, but when he learns his son Michael's sitting in a sailboat tied to the jetty, he leaps up and yells for him to come back on land.
Ellen thinks he's overreacting at first, but when she sees an illustration of a shark breaking through a boat hull, she flips out too.
That night, two bumbling locals go to a jetty to try to catch the shark. They tie a chain and a hook to the jetty, stick a holiday roast on the end, and throw it into the ocean. The tide takes it out to sea.
Brody continues researching sharks. He sees creepy images of sharks, beaches, huge prehistoric shark fossils, and shark attack wounds.
Meanwhile, those bumbling dorks have been waiting for a while. Suddenly something grabs the roast and starts dragging it out to sea. When the chain runs out, the jetty gets yanked in half, bringing one of the fishermen (Charlie) with it out to sea.
Suddenly we realize that the shark must have turned around because the dock's moving back toward Charlie struggling through the water. His friend tells him to swim for it, but the dock's getting closer!
As Charlie struggles to climb up onto the demolished jetty, the broken piece floats harmlessly to shore.
The next day, the harbor's crowded with amateur shark fishermen. Brody tries to maintain some kind of order as Matt Hooper, the shark expert, arrives on the island looking for him.
He finally gets Brody's attention and introduces himself. They decide to go perform an autopsy on Chrissie Watkins' remains.
A bunch of cockamamie fishermen hunt for the shark, chumming the water and dropping explosives into the water.
In the autopsy room, Hooper sees that the official cause of Chrissie's death is "probable boating accident." After examining the evidence, he says what we already knew: This could only be a shark attack.
Back on the dock, the excited fishermen display a bloody shark carcass. The newspaper's trying to stage a photo, and everyone thinks their troubles are over.
Quint pilots his boat past, smirking at all the bozos on the dock.
Hooper examines the shark and he's pretty sure this isn't the shark they're looking for. He wants to cut its stomach open, but Vaughn doesn't want to cause a scene in front of everyone.
Mrs. Kintner approaches Brody and slaps him in the face because he knew about Chrissie Watkins, but did nothing. Vaughn tells Brody she's wrong to blame him, but Brody knows she's right.
Vaughn plans to have the shark dumped into the ocean tomorrow.