Another week, another guest star for ABC’s "Castle." TV Line is reporting that “Scandal” star Matt Letscher will appear in the Season 7 premiere episode of the detective drama, which will air Monday, Sep. 29 at 10 p.m. EDT.

The show has already announced the additions of Marsha Stoller, from “The Closer,” and Rebecca Wisocky, from “Devious Maids,” to the cast for upcoming episodes. Apparently, fans can add Letscher to that list. The actor is most famous for playing Billy Chambers, the bad boy Chief of Staff to the Vice President, on the ABC show “Scandal.” He has also appeared in “The Carrie Diaries,” “Brothers and Sisters,” and “Eli Stone.”

In the “Castle” Season 7 premiere, Letscher will play a security consultant who “provides Beckett with information on the most important case of her life,” according to TV Line. This is sure to leave fans wondering what case that might be and what information Letscher’s character will provide. Could he be the key to finding out who tried to kill Castle in the Season 6 finale?

Fans will not have to wait much longer to find out, with less than a month remaining before the Season 7 premiere. Fans have been waiting since last season’s finale to find out who ran Castle off the road and why. Who knows if he and Beckett will be following through with their wedding after the shocking attack, but the couple will be back in action with new cases soon.

Castle returns on Sep. 29 on ABC. Are you excited that Matt Letscher is guest starring? Tweet your thoughts to Ja9GarofaloTV