First off, let me apologize for whiffing on a key plot-point in last week's recap, in which I wrote that Mos Def's Brother Sam character had been killed. I missed the 'Next week on 'Dexter...'" tease, where they revealed he would improbably live long enough to have a cathartic deathbed conversation with Dexter. As it turns out, Sam didn't die in the shooting, and opened 'Just Let Go' in intensive care after being shot three times. Sadly, he passed away in this episode, but not before making one last-ditch attempt to save his friend Dexter's soul.

'Just Let Go' was sad on several levels, and not just because we lost a character who was a source of wisdom and strength for Dexter. After Sam's death, Dexter was faced with a crucial turning point in his constant struggle between darkness and light. I don't know why I was disappointed that he chose the darkness, drowning Sam's killer Nick even after Sam begged him to forgive him. But it was a sobering reminder that our hero is also a murderous sociopath, just like Professor Gellar and the others he's obsessed with.

Then again, avenging the murder of his best friend, even if it was against his wishes, grounded the episode solidly in the gray area of moral ambiguity that 'Dexter' thrives in.