Castle

Season 2, Episode 4

Episode Title: Fool Me Once

Air Date: 2009-10-12

Overview:

When an Arctic explorer is killed during a polar expedition, the mysterious circumstances of his death take Castle and Beckett from the penthouses of Park Avenue to the halls of the CIA. But Castle's delight at the case's many twists and turns soon turns to frustration as he realizes that their elusive killer might just be fooling them all.