Boston Blue First Look: CSI Alum Marg Helgenberger Arrives And 'Upends' Sarah's Life, EP Teases

"CSI" alum Marg Helgenberger is making her way to Boston, and newly released photos offer a first look at her arrival.

The actress makes her "Boston Blue" debut in the Friday, November 13 episode (CBS, 10/9c), playing Gwen Silver, the estranged biological mother of Maggie Lawson's Sarah. The character is described as "a complex yet charming woman whose temperament is not unlike the climate of her Cape Cod home — unpredictable." According to the official breakdown, "Gwen returns to Boston with a very personal and emotional agenda just when Sarah least expects it. Though Gwen loves her daughter more than anything, her arrival adds a complicated layer to the Silver family dynamic."

"I think we can say that some events in Gwen's life have driven her to want to rekindle her connection with her daughter," co-creator Brandon Sonnier tells TVLine. "And this very much upends the new stability that Sarah is finding in her own personal life with [fiancé] Seth and [soon-to-be stepdaughter] Phoebe. While juggling her home life and her career, she is now faced with the opportunity — or challenge, however you look at it — of reconnecting with her estranged mother."

And don't expect Gwen's return to be a one-and-done affair. Although Sonnier won't disclose an exact episode count, he confirms that Helgenberger will appear in "several" episodes.

Elsewhere in "Boston Blue" Season 2, Episode 6, Danny (Donnie Wahlberg) slips back into his old rule-breaking ways after Boston P.D. discovers an abandoned baby inside a food delivery robot, while Sean (Mika Amonsen) and Jonah (Marcus Scribner) search for a fellow officer who has gone AWOL.

"Bloodlines" is directed by "Chicago Fire" alum Monica Raymund, who also helms the preceding episode featuring the return of "Blue Bloods" vet Will Estes as Jamie Reagan (airing Friday, November 6).

Helgenberger, of course, is best known for her long-running role as Catherine Willows on CBS' "CSI: Crime Scene Investigation," which she later reprised on "CSI: Vegas." Her other TV credits include "China Beach," "Under the Dome," and "All Rise."

Scroll down for additional photos from Helgenberger's "Boston Blue" debut, then hit the comments and tell us: Are you looking forward to meeting Sarah's mother?

Ian Watson/CBS

Ian Watson/CBS

Ian Watson/CBS

Ian Watson/CBS

Ian Watson/CBS