Unleashed! By Sarah Stegall Copyright © 2008 by Sarah Stegall Chuck Mondays on NBC at 9/8 “Chuck vs. The Gravitron” Written by Chris Fedak Directed by Allison Liddi Brown “Unleash the Casey.” — Chuck Bartowski Ah, revenge is sweet. Who has not longed to find the one that got away, the one that broke your heart, and turn the tables on them? This episode brings to a close (I hope) the story of how Chuck got past the pain of his ex-girlfriend’s betrayal, got a little payback, and grew up a little. Having been scorned by her in the past,…