And so we reach the last episode of Being Human’s fourth, possibly final, series. And it’s going out with a bang, literally.

Last week’s episode ended with Hal about to be ripped to shreds by werewolf form Tom. The War Child picks up a few hours after this event and the cliffhanger is resolved via a simple line. You can see why writer Toby Whithouse took this shortcut, as the finale has a lot to cram in, but it’s a little bit disappointing.

Last week’s conclusion also saw the long-awaited arrival of The Old Ones, with Mark Gatiss playing leader, Mr Snow. Unsurprisingly, Gatiss gets a fair chunk of the screentime and he’s great. His character is creepy and repulsive, highlighted no better than a scene in the cafe he shares with Hal. As Gatiss softly delivers his lines, the camera shows close-ups of his dirty teeth, fingernails and veiny skin. It’s very effective and unsettling.

Speaking of unsettling, this is quite possibly the goriest/ grossest episode yet. Hal gets up, close and personal with some maggots, and one vampire meets a particularly gruesome fate when he decides to enter a house uninvited.

Annie is left with an impossible decision – either kill baby Eve or let the world be taken over by vampires. It leaves you guessing right up to the end which choice she finally makes. Lenora Critchlow has been a bit side lined this year in favour of Tom and Hal, but she gets some of her best scenes here. There’s a terrific one late on with a line that will have fans cheering at the screen. It evokes Sigourney Weaver’s “Get away from her you bitch!” moment in Aliens.

With a little help from Annie, Alex (Kate Bracken) continues to get used to her newfound ghostly powers and wants to get revenge on Cutler. She’s still not happy with Hal either and the pair bicker like an old married couple. It’s fun and the two actors play off each other well. Their humour keeps the episode from being totally dark and bleak.

The finale is not flawless. The episode does feel less focused and there’s probably a bit too much going on. After all the build-up and apocalyptic future visions, The Old Ones don’t really do a great deal to further their plans, apart from Gatiss.

Naturally with this being a spoiler-free review, there’s lots we can’t talk about. But there’s a couple of characters that won’t be returning if the show continues. The finale lays the foundations and introduces a possible new threat. If Series 4 has proven anything though, it’s that this show can survive big changes.