Nadine Nicole Heimann

Walter must swim through the deadly La Brea Tar Pits when Team Scorpion helps a woman trapped in the tar before she runs out of oxygen. Also, without Paige's knowledge, her mother, Veronica (guest star Lea Thompson), "helps" Ralph maximize his troop cookie sales.

While processing the house where several showgirls were murdered, Sara is haunted by the terrified eyes and cryptic dying words of the sixth victim she discovers. (TV-PG)

On the night of a young man's 21st birthday, his friends take him out to celebrate, but when they turn up dead and he's found walking in the middle of the street covered in his friends' blood and wielding an axe, the CSIs must trace the events of the man's wild night to figure out just what happened. (TV-14)

Avery and her team investigate a new cyber threat that allows arsonists a less traceable method of starting fires in homes. Meanwhile, Elijah's ex-wife informs him she's starting a new job out of town and wants to take their daughter with her.