The episode begins with a guy and a girl stepping on to a beach after some snorkeling. The girl then proceeds to gather some drinking water in her flask, from the nearby woods. She then sees a trail of blood and follows it, and then much to her horror finds the body of a man with a battered face, lying on the floor of the woods. Jim meanwhile isn’t too happy with Callie not being able to make time to talk to him even on the phone. Carlos later tells Jim that the time of death of the victim is between “11am and 12noon today”. Also there are puncture wounds on the victim’s skull, which indicates that the murder weapon had a curved edge, and that the victim was attacked from behind.
Daniel meanwhile recognizes the victim as Brian Taylor, who won $130 million in a lottery “last year”. Daniel also informs Jim that the island on which the body has been found is only accessible by water. Later Jim and Jennifer run into a man called Neil Gannon, who privately owns the island. Neil tells the two that he has never seen Brian before, and also tells them that he lives on the island alone. Callie later apologizes to Jim for not being able to make time for him, but explains to him how busy she is, thanks to her impending board exams. Carlos then informs Jim that the victim’s liver and kidney had turned to “mush”, and also the deterioration of the organs had happened very rapidly.
Carlos concludes that the victim might have ingested a poison, and it was this poison that would have anyway killed him eventually, if the blow to the head hadn’t. Colleen later tells Jim that Brian was a destitute before he won the lottery, then winning it turned him into a “mini real estate mogul”. His next of kin is his younger brother Lucas Taylor, who is also the sole heir to all his property. It’s also been discovered that, Brian made a call to Lucas 2 hours before his death. Later Lucas tells Jim that, he hasn’t left the house for the last few days and his neighbors can corroborate that. Thus proving that, he wasn’t with Brian on the island, the day he died. Daniel meanwhile informs Jim that, Brian’s boat was found a mile away from where his body was found, and there is no evidence of foul play.
Also Brian was traveling alone. Jim and Jennifer also find out that Brian was camping on Neil’s island, from a few days before he died. The two then find boot prints near the campsite, and decide to question Neil, as he is the only one who wears boots on the island. Later Neil admits that he ran in Brian at the campsite, and told him to get off the property, as its private. He then tells Jim “the guy was a kook”, and describes to him how Brian had told him that he had bought the island. Neil then tells Jim about an “annoying” realtor lady, who kept hounding him all year to sell his island. He though turned her down. Neil tells Jim that the name of the lady is Megan Connor. Later Jim and Jennifer pay her a visit. She tells Jim, how Brian was obsessed with Neil’s island Rubicon Key, and wasn’t interested in buying any other island besides that.
Later Jennifer and Colleen inform Jim that, Brian had invested a million dollars in Lucas’s sunglasses business, but it went belly up. Brian then revoked his power of attorney that he had given Lucas, before the business going bust. Jim is also informed that, Brian was having a new will drawn up, in which Brian was planning to exclude Lucas out of his will. Later, Lucas hands Jim a huge basket of letters, which Brian received from people asking him for money. Lucas also tells Jim about Brian’s high school crush named Lourdes, who has died in an accident, and “Brian never got over her”. Jim then sees Lucas drinking from a bottle of mineral water, an empty bottle of the same brand of water was also found at Brian’s campsite. Lucas tells him it’s from the fruit basket that Megan gave Brian.
Carlos later informs Jim and Jennifer that, a tasteless poison was definitely delivered in the bottled mineral water found at the crime scene. Also they find out that Megan was trying to con Brian by trying to sell him Rubicon Key, using fake paperwork. They also discover that Megan had changer her hair style and hair color to match that of Lourdes. Later, when Megan is confronted about all of it, she protests telling them “I didn’t kill Brian; I was in love with him”. Jim is later informed that Neil was in the same school as Brian, and also Brian had suspected all along that Lourdes’s death wasn’t an accident but a murder. Jim and Jennifer then land up at Neil’s doorstep, but don’t find him there. The two then go searching for Neil on the island, as his boat is still docked on the island, hence they conclude that he hasn’t left Rubicon Key.
The two during their search also stumble on the murder weapon, which is a small shovel, with a curved edge. The two then get chased by a panther and climb a tree to escape it. Neil ultimately appears, and turns out, the panther is his pet. Neil sends away the panther. Jim then distracts Neil, jumps from the tree on him, neutralizes him and then arrests him for Brian’s murder. Neil tells Jim that he did not murder Brian, and when confronted about Lourdes, tells Jim what happened to her was an accident. He also tells Jim that he didn’t kill her, but felt responsible for it, but “Brian could never let go”. He then tells Jim that he tried to reason with Brian, and also tried explaining to him “what happened was Lourdes was an accident”.
Brian though it seems was “acting all weird”. Neil then tells Jim that he threw all the bottles of the mineral water into a recycle bin, with everything else that Megan gave him. He then reiterates that he did not kill Brian, but instead “felt sorry for him”. He also tells them that Brian was alive when he left him. Jim then tells Neil that he did not kill Brian, but “someone was really trying to kill you”. Later, Lucas is brought in by Jim. Jim then tells Lucas that his computer revealed the fact that, he had extensively researched on the poison that killed Brian, and also Lucas wanted Neil to suffer the same way Brian had suffered all his life, because of Lourdes’s death. Jim also concludes that Lucas hadn’t counted on Neil throwing all the bottles of the poisoned water in the trash.
Then, ironically Brian not finding any water drinking water anywhere else on the island, stumbled upon the bottles of poisoned mineral water in the trash, and drank from one of them. Lucas realized what had happened, when he spoke to a delirious sounding Brian over the phone. Thus to put Brian out of his misery, he went to the island and hit Brian on the head with the shovel. Lucas then admits to Jim that, after winning the lottery, all Brian cared about was getting back at Neil. Lucas then tells Jim he knew that, as long as Neil was alive, Brian wouldn’t be able to put Lourdes’s death behind him. Hence he did what he did to make his brother happy. Later Jim is visibly unhappy with how things are shaping up between him and Callie. The episode ends at this point.