Fans of ABC’s “Castle” were shocked at the end of Season 8’s second episode when Beckett (Stana Katic) dumped her new husband, writer and amateur sleuth Rick Castle (Nathan Fillion), to focus on solving her mother’s 16-year old murder case. The move took Castle and the show’s viewers by surprise, but the series’ showrunners are helping to pull back the layers of the bombshell decision.

“Castle” executive producers Terence Paul Winter and Alexi Hawley told Entertainment Weekly Monday that Beckett has complicated reasons for wanting space from her husband, adding that the separation could last for a while.

“The thing about it is that Beckett is ‘breaking up’ with Castle out of love,” said Winter, acknowledging that the explanation might sound a bit cliché. “It’s not because, ‘I can’t stand to be around you,’ or ‘I don’t think this is working out,’ or “I want to see other people” — that’s not what it’s about. It’s out of love. ‘I want to keep this man safe and the only way to do it is to put distance between us.’ That’s the struggle that we’re playing around with, especially in the first third of the season.”

That struggle will create a fun, new dynamic in the season.

“Nobody really understands why this is happening,” said Hawley. “Castle doesn’t even really understand why. Beckett just basically asked him to trust her that she has something to work out, so there’s definitely some unsureness going on but Castle is determined and therefore we have a lot of fun with that and you know, Beckett is in love with him, so that doesn’t go away even though she’s got this thing going on.”

Castle’s campaign to win his wife back will begin in the very next episode. According to the synopsis for episode 3, Castle will go undercover as a university professor when the body of a fraternity student at a local college turns up brutally murdered. Castle's disguise will help him and Beckett uncover some dark secrets at the school, including why the college wants to keep the circumstances surrounding the murdered student's death a secret. However, Castle’s true motivation is to get Beckett back with some of their old-fashioned, casework chemistry.

Watch the promo for episode 3 below:

Will Castle win Beckett back? And how long will it take? Fans will have to wait to find out. “Castle” airs Mondays at 10 p.m. EDT on ABC.