The actress will join the Castle cast for its upcoming season 6.

The House M.D alum has booked a multi-episode arc. According to TVLine : “Edelstein will play Rachel McCord a “tough and highly-skilled federal investigator” who plays a pivotal role in Kate Beckett’s decision about her future”

Last season ended with a big cliffhanger for the Caskett fans. Indeed, Kate Beckett was considering a move to D.C to work in a special task force at the U.S. Attorney general’s office. But of course, the main aspect of the finale was Castle’s marriage proposal.

Castle season 6 will premiere this fall.