The Mentalist is working to keep the series finale under wraps, but the name of a new guest star managed to slip out on Monday.

Who Will Blackmail Agent Abbott On 'The Mentalist'? The DEA & FBI Collide in 'Green Light'

Joyce Guy (Two Broke Girls, Parenthood) scored a role on the crime drama just under the wire.

"Booked the role of 'Judge Emily Hamilton' on the last episode of The Mentalist," Guy tweeted  on Monday. "Air dates to come in 2015. Yay!!"

Rigsby & Van Pelt To Return On 'The Mentalist'; Amanda Righetti & Owain Yeoman To Film For Finale?

The Mentalist is currently in its final week of filming. After seven seasons, the story of Patrick Jane will come to an end this February. CBS has yet to announce the finale date, but the evening's presentation will consist of two separate episodes - "Brown Shag Carpet" and "White Orchids."

Jane, Lisbon, and the FBI won't have a weak farewell. The series will go out with another pulse-pounding case, one that will involve a new serial killer named Lazarus. Red John is dead and buried but The Mentalist can't resist jumping back in the mind of another twisted killer once more.

Find out more when The Mentalist airs Sundays at 9 p.m. ET on CBS. Click the video below to see a preview for the series' next episode, "Black Market."

Tags: The Mentalist television CBS