Being Human, BBC Three‘s hit drama series about supernatural friends trying to live normal lives despite their unusual afflictions, is back – and, says writer creator Toby Whithouse: “It is, without doubt, our best series yet.

“A third series is a unique opportunity because it allows you to take all the best bits of series one and series two,” he says. “What we took from series one is the domestic element and very strong stories of the week with very strong guest characters. Series two had much more of an epic sweep and a breadth of ambition. Series three has allowed us to combine all those things.”

There are a few changes afoot when viewers meet the friends at the beginning of the new series. Werewolf couple George (Russell Tovey) and Nina (Sinead Keenan) and reformed vampire Mitchell (Aidan Turner) have fled their beloved shared house in Bristol and are looking for a new house to rent in Barry, Wales. They are also without ghost Annie (Lenora Crichlow), who is stuck in purgatory and desperately trying to escape.

Having been such an integral part of the first and second series, it was difficult to leave Bristol behind – but the new location has given the show an extra freshness that has helped in the story-telling.

“Our concern was that moving from Bristol and losing the iconic pink house would be detrimental to the show but, actually, we found that it really reinvigorated it,” explains Whithouse.

“It allowed us to kick off the series with a fresh start and with a renewed energy and provided us with heaps more material than we imagined.”

Leaving the memories of their much-loved former house behind, George, Nina and Mitchell settle into their new home – a kitsch bed and breakfast named Honolulu Heights that boasts many benefits for supernatural sharers – a large basement providing a safe and sheltered environment on a full moon, for one. Whithouse describes the new set as “jaw-dropping.”

“I’ve always said that Andrew [Purcell], our set designer, is a genius and every series we set him a huge new task and he never lets us down.

“The attention to detail is absolutely amazing. I’ve been on set goodness knows how many times but every time I go back there I’ll notice a new detail – something new that he’s popped in – it’s absolutely awe-inspiring what he’s done.”

Being Human has amassed a huge fanbase both in the UK and US and has even spawned a US remake due on screens in 2011. The pressure of maintaining the quality and popularity of a show which has such a vocal audience is “daunting”, says Whithouse. “I know how important the show is to its fans and so I’m aware that I have a responsibility not to let them down.

“But I think that’s good and quite enjoy the pressure and the challenge. They know the show almost better than I do and I relish the challenge of coming up with ideas that surprise them.”

Series three boasts an impressive array of guest-stars, including Lacey Turner in her first role after EastEnders as Lia, who Mitchell meets in purgatory; Robson Green (Wire In The Blood) as primitive werewolf McNair; Michael Socha (This Is England ’86) as McNair’s son Tom; Paul Kaye (It’s All Gone Pete Tong) as twisted vampire Vincent; Craig Roberts (Young Dracula) as teenage vampire Adam; Nicola Walker (Spooks) as social worker Wendy; James Fleet (Vicar Of Dibley) as George’s father George Snr; and Jason Watkins making an eventful return as vampire leader Herrick.

An online extension to Being Human will also launch online mid-way through the third series. Created by Toby Whithouse, and written by Brian Dooley, Jamie Mathieson and John Jackson, Becoming Human is set in a fictional college and will follow a new group of characters over nine episodes.

Throughout filming and transmission the Being Human blog offers fans a regularly updated behind-the-scenes glimpse into the show, with videos, blog posts and news updates from the cast and crew of the show.

Series three writers are Toby Whithouse (eps 1, 7 and 8), Brian Dooley (ep 2), Jamie Mathieson (ep 3) John Jackson (ep 4), Sarah Phelps (ep 5) and Lisa McGee (ep 6).