Castle kicks off a special two-part episode on Monday.

Titled "Setup," the first half will find our favorite duo investigating a robbery/homicide of a cab driver... only to soon learn that the victim was anything but a regular cab driver. He was at the center in a major conspiracy.

Enter FBI Agent Mark Fallon, played by former Heroes star Adrian Pasdar. He'll cause problems for Castle and Beckett as they all race to discover the truth about the murder victim and all in which he was involved. Get your first look at the installment now:

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