Before Castle and Beckett walk down the aisle, one of them will go on the run.
On Castle Season 6 Episode 22, Kate will discover that the man she's been following as part of her mother's murder investigation has been killed.
And now she's the primary suspect. Gulp.
In the following sneak peeks from Monday's episode, we see Beckett confronted by one of the men setting her up; and then we see a very different kind of meeting between loved ones at their swingset. Check out the clips now: