Catherine testifies in a murder trial in which a man is accused of murdering his own mother three years ago, but the suspect is found not guilty. Catherine, however, believes he did commit the crime and that he may also have killed two other people, so she sets out to find the other victims. Grissom prepares to leave on a four-week sabbatical.

With time, the weather, and the desert against them, the CSI team must work together to find Sara before she dies from the miniature killer's attack.

Sara questions her future as a CSI when a past case comes back to haunt her, the 12 year old Hannah, who has to back up her brother one more time with all new tricks up her sleeves.

Brass, Catherine, Grissom and Nick work the case of a female victim found in an apartment building with a gun shot wound. Drops becomes a person of interest during the investigation, even though he is still in jail.

After Warrick is shot in a Las Vegas alley, the CSI team comes together to deal with the aftermath.

The murder of a mother and her child seems to be connected to a murder case from 12 years earlier.

The CSI are called to three different crime scenes in one night that are seemingly unrelated, but each case's forensic evidence reveals a common link

Catherine revisits one of the very first cases she worked as a CSI when the convicted felon in the murder claims the verdict was based on faulty evidence.