of the episode, he expressed deep regret over solving a particularly depressing case. Grissom announced his retirement just as evidence comes to light that the Dick and Jane Killer, a serial killer from the 1990s currently serving two life sentences, did not act alone and that his accomplice had begun killing again. Rather than leave in the middle of a case, Grissom stayed on to help solve it, and ultimately proved instrumental in saving the life of a woman who would have been the killer's latest victim. The case closed, Grissom, having already had a series of one-on-one farewells with his co-workers, silently left the crime lab and departed for Costa Rica for a reunion with fiancée Sara Sidle, an allusion perhaps to his comments in a season one episode that when he left, people would not throw a party for him because he was not the sort of person whom people would get deeply involved with. He also says to Warrick in season two ("Ellie") that when he left there would not be a cake in the break room—he would just pick up and leave. Departure After reuniting with Sara Sidle, Grissom presumably remains in Costa Rica for a short time, before guest-lecturing at the Sorbonne, as noted in the tenth season. During the series' eleventh season, Grissom begins consulting for the Peruvian government on the etymology and physicality of the Inca . It is during this time that Sara and Grissom divorce, citing geographical differences. He later joins a group dedicated to protecting fish and wildlife in the Pacific, a role described as a "CSI at sea." After his activities lead him to the Port of San Diego, Grissom reunites with Willows and the CSI team in order to consult on a series of bombings in Las Vegas. During this case, he reconciles with Sidle, and the two sail off together in order to continue his work as a wildlife advocate. Return Grissom and Sidle both returned in the sequel series CSI: Vegas. Characterization Personality Early episodes revealed Grissom to be a witty, enthusiastic, and quirky scientist who had some sense of humor. He flirted regularly and seemed to be constantly in a hyperactive state. However, when he began to lose his hearing, Grissom retreated into himself and became easily irritated and unapproachable. After his surgery, he lightened up a bit but never returned to the whimsical science