Exclusive – Watch the "mad genius" first trailer for Mitchell and Webb's Back series 2

Following the death of his father, Stephen had been set to take over the family business – a pub in Stroud, Gloucestershire – but the sudden arrival of Andrew at the funeral threw those plans into disarray.

Over the course of the first series, Stephen became increasingly suspicious about his rival's true identity, with his family's dismissal of these concerns ultimately landing him in a psychiatric facility.

That's where we find him at the beginning of series two, claiming to be rehabilitated and ready to re-enter society, but secretly planning to expose Andrew's true nature once and for all.

Channel 4 shared the following the trailer with RadioTimes.com, showcasing the fact the feud between the foster brothers is as bitter (and hilarious) as ever, while also giving a glimpse at what we can expect from the supporting characters.

The first series of Back premiered in September 2017 and the show was renewed for a second shortly after, but the project was delayed initially due to health problems suffered by Webb.

Filming was interrupted once again amid the coronavirus pandemic, but was finally completed in September ahead of its scheduled return date sometime next month.

Expectations are high after the critically acclaimed first series, which fans agreed was a worthy successor to the legendary Peep Show, which aired its final episode in 2015.

Back also stars Penny Downie (The Crown), Louise Brealey (Sherlock), Geoffrey McGivern (Ghosts), Olivia Poulet (Doc Martin), Oliver Maltman (Liar) and Jessica Gunning (Trollied).

Back series two premieres on Channel 4 in January. While you're waiting, check out our TV Guide to see what's on tonight.