Credit: Bob D'Amico/ABC

It’s been a long and winding road to the altar for Richard Castle (Nathan Fillion) and Kate Beckett (Stana Katic), but the crime-solving partners-turned-soulmates are almost there! They’ve survived bomb threats, kidnappings, and attempted murder — but they’ve got one last obstacle to hurdle: Beckett’s current husband?!

That’s the set up for Monday, May 12’s Season 6 finale, “For Better or Worse.” Beckett and Castle — that’s Caskett to you noobs — are ironing out the final details of their nuptials just 72 hours prior to the big day, when Kate discovers that she’s still a Mrs...to someone else (guest star Eddie McClintock)! Will this ruin her big day with Rick?

Read on for the official synopsis for “For Better or Worse”:

“Castle and Beckett's long-awaited wedding is almost here, but when a shocking surprise threatens to ruin the big day, they are sent on a wild mission filled with masked men, angry bikers and a charming ne'er-do-well from Beckett's past.”

Watch the sneak peek below, and don’t forget to sign up for a reminder so you don’t miss the exciting affair!

What do you think Castle and Beckett’s wedding will turn out like? Will they even make it down the aisle? Share your thoughts in the comments below.

Castle’s Season 6 finale, “For Better or Worse”, airs Monday, May 12, 2014 at 10 p.m. ET on ABC.


Don't miss the episode.