Kyle Gallner and Madeleine Martin

Veronica Mars alum Kyle Gallner and Californication's Madeleine Martin will guest-star in an upcoming episode of Criminal Minds to be directed by star Matthew Gray Gubler, TVGuide.com has learned exclusively.

Check out photos from Criminal Minds

Gallner and Martin will play siblings James and Lara, who believe the twisted delusions their dead mother passed on to them.

The episode will be the 19th one of the season and will mark the third time in the director's chair for Gubler. The actor, who plays Reid, made his Minds directorial debut two years ago and last year helmed Paget Brewster's first exit from the show. (Brewster announced earlier this week that she will leave again at the end of the season.)

Paget Brewster to exit Criminal Minds at the end of the season

Gallner, who played Beaver on Mars, has also appeared on Smallville as Bart Allen and on CSI: NY as Mac's stepson. Martin stars as Hank's daughter, Becca, on Californication, which is currently in its fifth season.

Criminal Minds airs Wednesdays at 9/8c on CBS.