Season synopsis
Contains spoilers for this season and earlier seasons.
The search for Morgan and Ellie reveals that the apparent abduction story has concealed Ellie’s involvement with one of the killers. Morgan escapes her restraints, but Ellie shoots both their captor and Morgan, then tries to blame him. The physical evidence exposes her story. Brass finds his former wife Nancy murdered. Ellie holds him at gunpoint, but he takes the weapon and police arrest her. Morgan survives, leaving the two fathers facing very different outcomes after the same investigation.
The team’s later work ranges from a deadly nightclub fire to a murder involving an electronic smart house, where FBI cyber specialist Avery Ryan assists. Catherine returns when evidence reopens a case from the beginning of her CSI career. Greg must also defend his earlier work when a man claims that he was framed. These cases keep the lab examining its own past alongside new crime scenes, with Russell and Finlay continuing to lead the investigations.
The finale connects a present-day murder to money stolen decades earlier and the childhood death of a boy named Scotty. Retired deputy Sam Bishop contributes the forensic experiments he carried out during the original investigation. The evidence ultimately implicates his daughter Karen, who accidentally suffocated Scotty and later killed another participant over the hidden valuables. Brass, meanwhile, visits Ellie after she overdoses on medication in prison. She survives, and he decides to support her despite the killings she committed. He cannot abandon the only family member he has left.