DON AND MEGAN MUST FIND A DISGRUNTLED FORMER EMPLOYEE OF A PHARMACEUTICAL COMPANY WHO IS TAMPERING WITH OVER-THE-COUNTER MEDICATIONS, ON "NUMB3RS," FRIDAY, NOV. 25

Lou Diamond Phillips ("La Bamba") Guest Stars

"Toxin" -- A former chemist of a large pharmaceutical company is discovered to be tampering with medication and Don and Megan must track him down, on NUMB3RS, Friday, Nov. 25 (10:00-11:00 PM, ET/PT) on the CBS Television Network. Jefery Levy directed the episode written by Ken Sanzel.

Lou Diamond Phillips ("La Bamba") reprises his role as Special Agent Ian Edgerton.

When several people in Los Angeles suffer from seizures as a result of product tampering of over-the-counter medications, Don and his team discover that a former chemist from a large pharmaceutical company is to blame. While tracing the culprit to the Sibley mountains, the team meets up with Special Agent Edgerton (Lou Diamond Phillips), who is tracking a cattle rancher-turned-federal fugitive for selling tainted beef and killing a U.S. Marshall. Megan figures out that their meeting isn't random, as the two fugitives have something in common.

Don Eppes: Rob Morrow
Charlie Eppes: David Krumholtz
Alan Eppes: Judd Hirsch
David Sinclair: Alimi Ballard
Larry Fleinhardt: Peter MacNicol
Megan Reeves: Diane Farr
Colby Granger: Dylan Bruno
Agent Ian Edgerton: Lou Diamond Phillips
Bob McHugh: Connor Trinneer
Bill Yardley: Patrick O'Connell
Rob Evans: Nick Kiriazis
Taylor Brindell: Mark Harelik
Tate Gilliam: Owiso Odera
Wife: Elyse Marie Mirto
Mrs. McHugh: Cynthia Preston
Sheriff's Deputy: Kristin Proctor

RATING: TVPG-LV