CSI Scoop: X-Files' Annabeth Gish Books Major Arc as Catherine's [Spoiler]

The truth is out there about Marg Helgenberger’s hush-hush exit plot on CSI, and I have a hunch X-Files vet Annabeth Gish figures squarely in the middle of it.

The actress has landed a three-episode arc as Laura, an old friend of the soon-to-depart Catherine. When the two reconnect after 20 years apart, Cath discovers a surprising terror underneath her pal’s cheery exterior — a terror that she suspects is linked to her powerful bazillionaire hubby whose company may or may not have been involved in some very shady goings-on.

Gish’s first of three non-consecutive episodes is slated to air during November sweeps. She most recently appeared as shrink Anne Sullivan on ABC Family’s Pretty Little Liars.

Producers are also casting the role of an FBI agent who comes to Vegas to work on a big case — and sleep with Catherine.