CSI: Immortality

The two-part series finale "Immortality" brings back Gil Grissom (William Petersen) and Catherine Willows (Marg Helgenberger) to investigate a bombing at the Eclipse casino in Las Vegas, where FBI agent Catherine Willows is tasked with leading the investigation alongside her colleague Sara Sidle (Jorja Fox). As the team works to restore safety to the streets of Las Vegas, Russell decides it's time for him to "head East," while Grissom confesses his love for Sara, setting the stage for a fitting conclusion to the series.