SPOILER ALERT: This weekly blog is for those who are watching Being Human on BBC3. Don't read on if you haven't seen episode three

Dan Martin's series three, episode two blog

BEING HUMAN Series 3, Episode 3

The One Where … Zombies emerge in the Being Human universe; Mitchell has a Single White Vampire moment; Nina gets pregnant; and Annie and Mitchell get it on.

"We're a supernatural hostel now are we? What next, a mummy?"

Nina certainly has a point. After last week's caper with Little Orphan Adam, this week they pick up another waif, and indeed a stray – Sasha, "like the Beyonce album," a Rugby Wag who died in a car smash while text-driving. Her soul stays on this side while her body decays. In other words, she must be a zombie. It's a clever bit of internal mythology that zombies don't just walk the world like vampires and werewolves and ghosts. Sasha and the others were "created" as a direct result of death's door being blocked in the hospital when Mitchell went back for Annie. It's their fault, so Sasha is their responsibility.

Sasha is proper comedy scary, with inadvertent "Here's Johnny" moments at all corners, and a disgusting bit with a rugby trophy. But with the housemates living in relative domestic bliss, the good souls they are can do nothing but help.

Sasha's real purpose though, is to deliver her inspirational "I wish I'd done more" deathbed speech, which serves to hurry along two of the plot strands that might otherwise have taken a whole season to work through. As predicted last week, Nina is pregnant (it transpires the contraceptive pill has little effect on werewolves) and her horrified reaction sheds more light on her troubled past and presumably those scars on her back. Post-Sasha, she comes to terms with giving birth to a little hairy baby. This concern for lupine biology will presumably feed back into the return of McNair and Son.

Even more excitingly for fan-fic purposes, Mitchell and Annie have declared their love. And it seems they can even kiss properly! He faces up to how much he missed her, she dismisses his killings as "the man he used to be". Lovely as it is to see Aidan Turner get some lighter stuff to do, it's all beginning to look rather cosy. If only Annie knew the full extent of what he'd been up to, and how recently …

Supernature

Simon Pegg will have a field day with this one. After complaining loudly on these pages that ZOMBIES DON'T RUN like they did in Charlie Brooker's Dead Set, hell knows what the horror purist is going to make of the deviating zombies of Barry. They can run, they can also talk, they can also get drunk and snog inappropriate men in nightclubs without eating their brains. They can also experience touching moments of emotional truth and inspire those around them. Letting himself off the hook somewhat, the writer weaves in some doubt among the gang about whether they should call Sasha that. But as is pointed out, she's a dead person with a rotting body, so what is she if not a zombie?

Pop culture notes

None of the housemates look like they would be Professor Green fans, so presumably Annie playing his I Need You Tonight is to make Sasha (who clearly would be a Professor Green fan) feel at home. I'd have put Annie more as an indie girl. Or a Glee fan.

Mysteries

It's looking like the aftermath of the Box Tunnel Massacre is going to be the big story arc this year. Which is good because a year after the fact it was almost easy to forget that his friends didn't know Mitchell was behind it and storywise let him off the hook. The antics of tragic superfan/stalker Graham suggest this is going to follow Mitchell around for the rest of the fun. And that none of this is going to end well…