While ABC's Castle will be airing some more light-hearted episodes after the weighty two-parter, they will be getting back to more drama before long.

'Castle' Stars Still Need To Renew Contracts With Future Uncertain

As is commonplace with Castle, the series is returning on Monday with a lighter episode in the wake of a more dramatic arc. However, Castle show runner David Amann told Entertainment Weekly this week that they would be heading towards another darker episode soon, this one having to do with Ryan (Seamus Dever).

"We have a Ryan-centric episode coming up that's a dramatic episode," Amann said. "He's been moonlighting working security and he's protecting an important person. Something goes horribly awry while he's doing it, and he gets embroiled in trying to find out what exactly happened."

'Castle's Beckett 'Looking Ahead' To Children With Rick In The Future?

The series will also be going back to the "vanishing" storyline that bridged the gap between last season and this season, with Castle mysteriously disappearing on his wedding day.

"We touched on the missing time here more in terms of the feeling it was bringing out in the characters - specifically the first time Castle is looking at the tape Beckett made, he's kind of experiencing what she experienced, except probably a worse version, because he knows she's in the clutches of Jerry Tyson," Amann previously told TVLine.

He added that this storyline would be "explored in a greater depth when we get to Episode 20."

Castle airs Mondays at 10 p.m. ET/PT on ABC.

Watch the promo for the next episode of Castle here:

Tags: Castle television ABC