CSI: Crime Scene Investigation is already filming for it's monumental 15 th season, but the cast isn't starting off the new year by working on the premiere.

Instead, the series is shooting slightly out of order and kicking off production with episode 2 instead. Directed by Frank Waldeck, the untitled installment will be the first piece the CBS drama has filmed without Captain Brass (Paul Guilfoyle).

Despite losing the long-time character, the CSI writers are promising an exciting year - one that could possibly include a season-long killer.

"We're very excited about what we have planned for you this year. It's super dark and twisted," tweeted the CSI Writers' Room in early June, later reassuring viewers that the season will be "not painful at all! It will be a fun season (and dark), but not painful. Fun!!! :)"

While many regular season series do not start shooting until the middle of July, CSI headed back to work early in order to push forward their premiere date.

"We are starting early this year so we can finish a little early," the CSI Writers' Room explained. "Leaving time for CSI: Cyber to air in our time slot."

Although little is known about episode 2, actor Richard Speight Jr. (Supernatural, Band of Brothers) has announced that he will make a guest appearance.

Find out more when CSI returns to CBS this fall. Click the video below to see a preview of the series' most recent episode, "Dead In His Tracks."

Tags: CSI: Crime Scene Investigation television CBS