11 Grim TV Moments You Won't Watch Again

Dexter came out of the gate strong with a fascinating premise - a serial killer who quelled his lust for murder by only targeting others who partake in his off-work hobby - that wound up suffering greatly due to its inability to reach a satisfying conclusion. It's the modern case study in a show overstaying its welcome.

But it was never better in its fourth season in which Dexter (Michael C. Hall) finds a counterpart in another killer (John Lithgow) who has also managed to temper his urge to kill and balance it with an average family life. At this point, Dexter's on-again, off-again relationship with romantic interest Rita Bennett (Julie Benz) has consummated in marital bliss and it appeared as though he was well on his way toward breaking old habits. Bennett's own tragic upbringing synched up with Dexter's, but marital strife starts early.

By the season's end, it's apparent to anyone not paying close enough attention that there really is no such thing as a satiable serial killer, and our lead is forced to take out Lithgow. Not before, however, he leaves one final victim in his wake: Bennett, who Dexter finds in the bathtub. It's a gory mess, with Bennett's child weeping in his mother's blood, but it also proves what we all knew: there was no going back.