Tonight’s episode opened with a huge pool party at the Golden Nugget. During the party a woman spots a shark in the pool. As people ran screaming the shark attacked a woman laying on a raft and bit off her arm.  Catherine and her team arrive at the pool while the shark is still circling inside the pool and they had to wait for Dr. Holloway, a shark vet to remove the shark before they could get the body.

Dr. Robbins and Langston found that the woman who died did not die from the shark attack, she was injected in the back through the raft she was on with something and the shark was attracted to the blood in the water.

As the team investigated they found that the woman who died was injected in order to rob her and was not done as intentional murder. Wendy got back from her trip to Portland and told Hodges that she had gotten a new job working in the Field and she was leaving.

Catherine and Ray confronted Macklin the owner of the competing hotel to the one that got the shark after they found that Dr. Holloway had lied about it being a local shark and they were able to pull serial number off the shark. Macklin confirmed that he had gotten rid of the shark the week prior through Dr. Holloway. Nick and Sara went to confront Holloway and found him floating dead in Macklin’s fish tank.

Holloway died from Co2 poisoning. His scuba tank was filled with car exhaust. Test that Hodges ran showed that the Co2 came from Boozell’s vintage car. Upon investigating where the car was the night before.

Catherine and Sara found that while Boozell was visiting Macklin, Macklin had his valet fill Holloway’s tank with Co2. Brass and Catherine confronted Macklin and told him they knew he paid Holloway to put the shark in Boozell’s tank and he was going to jail for the murder of Dr. Holloway.