CSI: Crime Scene Investigation fans will meet the woman that brought Sara Sidle (Jorja Fox) into the world, I have learned exclusively.

This season’s fifteenth installment, titled “Forget Me Not” written by co-executive producer Andrew Dettmann, will finally introduce Laura Sidle in an episode that places Sara under the microscope. The history of Sara’s family has been mentioned in episodes such as “One Hit Wonder” from Season Three and “No Humans Involved” and “Nesting Dolls” in Season Five. In the brief moments of history given on the Sidle matriarch viewers have learned that Laura killed her husband, and was committed to a psychiatric facility forcing Sara to be placed into foster care. So who will portray Mama Sidle?

Actress Kay Lenz has scored the pivotal role, sources confirm to me exclusively. Lenz, a Daytime Emmy winner, will first appear in the February 20 episode. Described as the victim of a very hard life, Laura Sidle has been transported from a care home to the hospital due to alcohol poisoning. Confused, but apologetic, she has no idea that she is a pawn in the machinations of a nefarious plot to sabotage Sara. But she is delighted to see her daughter, so maybe all is good between the two of them now? Probably not.

In addition to The Tick Lenz has appeared in, but not limited to, Magnum, P.I., Gunsmoke, ER, House and Southland. Production on the episode started this week.