Dexter villains just get wilder and wilder, with Season 6 unleashing a pair of Apocalypse-fixated nuts on the hapless city of Miami, which has already had its fair share of homicidal sociopaths in the past decade.

SPOILERS FOR SEASON 6…

Dubbed the Doomsday Killers by the biblically-aware Miami media, the pair’s contribution to the show’s long track-record of violence is to stage gory tableaux of prophecies from the Book of Revelations, some of which involve Saw-style traps that the police themselves set off.

As ever, their combination of artistry and arrogance is too much for Dexter to resist and despite the third-degree emotional burning he got from the Trinity killer he soon finds himself in his fatal role of the lone hunter, stalking them behind the Miami police department’s back in order to learn their secrets and then kill them.

However, this time around Dexter’s conviction that people with a ‘dark passenger’ don’t change is challenged when he meets reformed killer Brother Sam (Mos Def) and, despite initial scepticism, learns that he really is the good Christian he claims to be. Suddenly he’s being confronted by the ambiguity of human nature – and not just in Brother Sam. What if he himself isn’t the unequivocally murderous person he thought he was? What if the Doomsday Killers aren’t what he initially thought?

The questions get a little more urgent when Dexter’s son Harrison gets a place at a devoutly-Catholic nursery and the matter of religion comes up. The Holy Trinity, Dexter’s duality, the Doomsday Double Act, all conspire to blunt our hero’s killer instincts about people’s worth – and their worthlessness.

Meanwhile, Dexter isn’t the only one whose principles get tested. Deborah’s promotion to Lieutenant causes disruption all round and puts her in a painful ethical dilemma…

This isn’t the most ebullient Dexter season. The creators of the show have resisted the soap-opera appeal of procuring Dexter a new love-interest every season and this time he doesn’t get any – well, apart from one encounter when he’s having a moral crisis. Dexter’s main passion in life is executing people like himself and the writers take care not to sugar-coat his sombre, solitary nature and dilute the show’s crime focus by putting too much emphasis on romance.

The same goes for the other characters, who aren’t exactly models of patient love themselves. There’s a divorce – really a post-divorce since the actual divorce happens casually and forlornly between seasons – and the only marriage proposal leads to a break-up.

There’s also that Doomsday Killer(s) reveal. Perhaps it’s not quite on the scale of the twist that made Season 4’s finale so devastating, but it may well leave you feeling a bit gutted.

The danger with twists is that they give you surprise at the expense of believability and psychological insight. This is perhaps a problem in Season 6 and you may find yourself running back over previous episodes trying to figure out what really happened and whether you were being treated fairly as a viewer. On the whole we would say that the script-writers played fair, but they certainly gave themselves a lot of license (although arguably Dexter’s frequent chats with his dead dad make the twist jar less than it would in other shows).

Perhaps the real shocker is the final episode’s cliff-hanger ending, in which a corner-stone of the series, Deborah’s absolute trust in her big brother, is profoundly – and you’d assume permanently – undermined, having already been tested by her discovery that she’s in love with him. With at least two more seasons still to come, one can only wonder where Dexter’s creators will take us next.

Released on DVD and Blu-ray on Monday 18th June 2012 by Paramount Home Entertainment.

> Buy the DVD boxset on Amazon.

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