The Sixth Doctor returns with companions Flip Jackson and Constance Clarke in three new Doctor Who adventures starting with today's release, The Behemoth.

We take the TARDIS back in time with a Georgian tale on Earth, as Colin Baker stars as the Sixth Doctor with his companions Flip and Constance, played by Lisa Greenwood and Miranda Raison.

Bath, 1756 – and a very dashing gentleman known only as the Doctor is newly arrived in town, accompanied by his lady friends Mrs Clarke and Mrs Ramon. He’s created a stir among the gentlefolk of Georgian high society – and a stir in the heart of merry widow Mrs Theodosia Middlemint, rumour has it.

They are not the only strangers from abroad causing tongues to wag, however. The mysterious Lady Clara, come from Amsterdam in the company of the noble Captain Van Der Meer, has the whole of Bath agog. Who is she, really? What is she, really?

But there’s something terrible beneath the veneer of Georgian gentility. As awful a horror as the Doctor has ever exposed, hidden inside Balsam’s Brassworks. Something that needs to be brought to light, for the sake of all humanity.

We asked the writer of this tale, Marc Platt, why he chose such an elaborate tale for the Sixth Doctor. Marc explained: “Colin Baker had asked for a purely historical story which gave me an excuse to collide three ideas that I'd been mulling over for a while. High society in the Georgian period seemed like a natural fit for the Sixth Doctor at his most flamboyant.

“It's 1756 and the story begins in the spa town of Bath, a playground of the upper classes, but the dark underbelly of English society is soon uncovered in all its prurient glory. Close by is the port of Bristol, which was a hub for some of the worst excesses of the Slave Trade. Two worlds in collision and collusion. The story is peopled with slightly grotesque characters, who would be entirely at home in a play by Sheridan or a painting by Hogarth. Merriment, corruption and some surprising romantic entanglements for each of the TARDIS crew.

“It's a period piece, but there are a couple of real-life characters. The mysterious Lady Clara (no, not that Clara!) and her Dutch Captain escort – an exceedingly odd couple who toured 18th century Europe thrilling the public wherever they went. They are bizarre, perfect Doctor Who characters, and I’ve wanted to use them for years.”

This new tale is available at £14.99 on CD or £12.99 on download. All CD purchases unlock a download exclusive which works with the Big Finish app.

Or you can save money by getting a subscription to the Doctor Who Main Range. When you subscribe you'll get 30% off the price, free specially recorded Short Trips stories, PDFs of the scripts and extended downloadable extras. You can subscribe for either 6 or 12 releases.

Coming up next in the Sixth Doctor trilogy, the second (‘middle’) of these tales is Doctor Who – The Middle.

It’s L/Wren Mrs Constance Clarke’s birthday – and Flip is determined to make it an anniversary to remember.†¨†¨

The futuristic colony of Formicia, where the pampered populace pass their days in endless leisure, seems the perfect place for a ‘Wren Party’. But all is not as it seems. Looking down from the Middle, the skyscraping tower that ascends as far as the colony ceiling, Formicia’s overseers can see that the Doctor doesn’t fit in – and it’s not just his coat that makes him conspicuous...†¨†¨

‘The End is the Beginning’, say the propaganda-like posters all over Formicia. Because to be part of this perfect society comes at a price. And the Doctor's already in arrears.