Siobhan Finneran Credit: Dave M. Benett/Getty Images

Get ready to say goodbye to yet another Downton Abbey regular. TV Line reports that actress Siobhan Finneran -- a.k.a. Sarah O'Brien, Lady Grantham's maid -- is leaving the acclaimed PBS series after three seasons.

"I'm not doing any more," the British star told the U.K.'s Mirror. "O'Brien is a thoroughly despicable human being -- that was great to play."

Finneran's character was indeed a troublemaker. During her tenure as Lady Grantham's maid, she schemed, meddled, and exploited the house for her own selfish purposes -- even at the expense and health of her employer.

According to TV Line, O'Brien will depart the Yorkshire country estate during the time jump between seasons three and four. Her exit comes on the heels of two other major sendoffs, for Sybil (played by Jessica Brown Findlay) and Matthew (Dan Stevens).