Buckle up, Castle fans. Things are about to take a turn for the serious on Monday's "Target."

The first hour of the show's annual two-parter, this episode will first focus on a seemingly typical murder investigation, as the team is on the crime scene in the following sneak peek:

But a further examination of a surveillance video makes it clear this case is anything but ordinary, as Beckett, Castle and company witness an abduction:

Finally, it's a father's worst nightmare, as Castle and Beckett follow up on the missing girl, only to learn that Alexis was also involved. In the worst way possible:

Visit TV Fanatic soon after this Castle Season 5 episode airs for our weekly recap and review!

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.