The Bad Moon Arising... We caught a brief glimpse of the velvet-voiced Mr Snow last week, but we're properly introduced to the ancient leader of the Old Ones (a brilliantly sinister Mark Gatiss) in this series finale. In a final flash-forward to 2022, we see Snow commit acts of horrific violence and spout a string of utterly fantastic lines. Toby Whithouse clearly had a ball writing for the character - our favourite Snow-ism has to be, "I don't intend to - you're delicious".
Hal's terrified reaction to Snow is a nice touch - if he's scared, the viewer knows we're really in trouble - and the eventual face-off between the two vampires is electric.
It's a real pity that, by episode's end, Snow is no more - Gatiss makes a phenomenal impact with relatively little screen time. That said, Steven Robertson - who you may remember from playing twin killers in Luther - makes a strong first impression as the "silent, modest" Mr Rook - series five's chief baddie?
Back in the present, Cutler (Andrew Gower) expects humanity to be in turmoil following Tom's public transformation, but his efforts, it seems, have been in vain. Yes, last week's cliffhanger is resolved a littly too neatly, but another cracking line from Gatiss - "Thanks to you, breweries the world over are safe from piss-ups" - helps a little.
With Cutler cast out, Tom and Hal plan a noble, self-sacrificing strike against the Old Ones, but there's a feeling of inevitable dread that permeates 'The War Child' - somehow we know that their plan will fail and that it will all ultimately come down to the fate of baby Eve.
This powerful, almost unbearably tense finale cleverly draws together strands from this year's episodes. Even Tom's apparent enthusiasm for building a swimming pool in the back garden, which this writer had dismissed as simply a running gag, is key to how events unfold...
Cutler breaching the entrance to Honolulu Heights, burning himself terribly in the process, is a truly horrific sequence, and props to Andrew Gower for a brilliantly odd and unnerving performance.
More Eve-related shocks come as the naive Tom hands the child to the Old Ones, but the real surprise is yet to come. Eve's final fate - killed by Annie, along with Mr Snow, to save the world - can't be called predictable, but, like all the best tragedies, it's sadly inevitable.
And that, it transpires, was Annie's unfinished business. Ever since Alex (Kate Bracken) popped up as a ghost last week, Being Human fans have speculated that she was being groomed as Annie's replacement and it's fairly obvious from this episode's opening scenes that this is indeed the plan, as our new trio lead the A story.
Annie gets a happy ending - of sorts - as she's reunited with baby Eve in Purgatory and sees all of her lost friends on the other side. It's nicely handled, but a couple of things disappoint...
After a brief glimpse of her full potential in 'A Spectre Calls', it's a pity that the idea of 'Super Annie' was never really explored. But the bigger crime is robbing the audience of the chance to witness Tom and Hal's immediate reaction to Annie's departure. Without that, her exit lacks some of the emotional impact it might otherwise have held.
Still, in her final performance, Lenora Crichlow excels as an emotionally traumatised Annie, facing the prospect of allowing a child to die for the greater good. A big thanks for your work over the past four years, Ms Crichlow, and all the best for the future.
But as terrific as she's been, Being Human proved this year that it cannot only survive but thrive following major cast changes. Despite the reservations of some fans, this has been an utterly fantastic series, deftly balancing drama and humour.
Damien Molony - a clear star in the making - has been a revelation as Hal; his performance was funny, moving and deeply unsettling all at once. And while he's perhaps not been gifted with the same range of material as his co-star, Michael Socha has also delivered the goods as the wide-eyed, loveable Tom. It's been great fun to watch the pair's on-screen partnership develop.
BBC schedulers, a fifth series of Being Human - starring the all-new lineup of Hal, Tom and Alex - is an absolute must.
Let us know what you thought of the Being Human finale below!