Welcome Ann Kelso, a police officer in 1978 who, during the course of the strangest investigation of her career, happens upon an old battered Police Box, and its eccentric occupant…

‘As the series begins, the Doctor has just left Leela behind on Gallifrey,’ says producer David Richardson. ‘He’s alone and hasn’t even opened the box containing K9 Mark II yet - and then suddenly he’s running for his life from undercover aliens, and dragging a stranger called Ann Kelso to safety…’

Ann is played by Jane Slavin, who has been a regular guest artist in The Fourth Doctor Adventures since 2011, and also played Onya in The Paradise of Death which starred Jon Pertwee and Elisabeth Sladen. ‘We actually created the role for Jane,’ says David. ‘Tom and Jane work brilliantly together - there’s an instant, indefinable chemistry between them every single time they record together at the studio. In real life, Jane just naturally feels like one of the Fourth Doctor’s companions - and so it was inevitable that eventually she would play one…’

‘Part of the excitement of Doctor Who is the secrecy surrounding everything,’ says Jane. ‘For about a year now I've wanted to tweet, “K9 called me Mistress!” We had to be so secretive I didn't know what I was doing myself until about two weeks before we recorded the first episode. Ann is everything you would want from a companion, in real life, in a TARDIS; in a crisis, she's brave and funny and absolutely up for adventure, regardless of risk. Justice is way more important than self-preservation. Let's just drop everything and zip off to a different planet without so much as a second look at Earth! She's either brilliantly brave or mad as a bat.'

“I suspect she's brave. I mean, she's been a WPC in 1970s Britain, so she's already fought dinosaurs who still think women should be ironing their husband's underpants. I love her. Working with Tom is without a doubt a dream fulfilled. I hope we get to do hundreds more together. Someone once said they envied my real life - well, that day I'd been in the TARDIS all day with Tom defeating some alien enemy on a planet I'd never heard of the week before, with John Leeson calling me mistress and (director) Nick Briggs laughing right into my ears and I had to agree, as real life goes that's pretty hard to beat.’

The Fourth Doctor Adventures - Season 8 will be released in 2019 on CD (over two box sets) and download. The season has an overall title of The Syndicate Masterplan and, because all eight episodes form one ongoing story, the box sets will be out only one month apart, in January and February 2019.

The run starts with The Sinestran Kill by Andrew Smith, in which aliens have become involved in the London crime scene in 1978. Frank Skinner (Mummy on the Orient Express) plays DCI Scott Neilson while Glynis Barber (Blake’s 7) is Kathy Blake. Ann takes a trip into history in The Enchantress of Numbers by Simon Barnard and Paul Morris, as she and the Doctor meet Ada Lovelace (Finty Williams), the daughter of Lord Byron and a Victorian computer pioneer. But what are the bird-masked strangers that are stalking the local village?

Ann’s first trip into space then takes her to the Planet of the Drashigs, as Phil Mulryne throws the Doctor, Ann and K9 into a theme park where different species of Drashigs are about to run wld. Fenella Woolgar (The Unicorn and the Wasp) plays Vanessa Seaborne. ‘Who doesn’t love the Drashigs?’ says executive producer Nicholas Briggs. ‘The huge omnivores from Carnival of Monsters are back in force - and this time they’re in bigger numbers and deadlier than ever!’

The first box set ends with The False Guardian, which leads into the second box set’s Time’s Assassin - two scripts written by Guy Adams, and guest starring John Shrapnel, Blake Ritson and Jon Culshaw.

‘I’d love to say more about these episodes,’ says David, ‘but there are too many surprises in there to spoil. This is the point when the overall story steps into high gear…’ In Fever Island by Jonathan Barnes the TARDIS lands on a misty, mysterious island where scientists are conducting strange experiments, and all may not be as it seems. Gethin Anthony (Game of Thrones) plays Jason Vane. The season ends with a four-part story, The Perfect Prisoners by John Dorney. Ann Kelso’s investigations are reaching their climax, and the Doctor will have to make one of the hardest decisions of his many lives.

Doctor Who - The Fourth Doctor Adventures Series 8: The Syndicate Masterplan is released in 2019 and can be pre-ordered in a variety of ways: all eight stories in two boxed sets can be Subscribed to for £40 on Download or £45 on CD. Alternatively either boxed set can be bought for £20 and £25 respectively, or digital versions of any of the eight stories are available individually for £8.99.

Check out our Doctor Who - The Fourth Doctor Adventures range, which includes Bundles on the first five series, and the chance to Subscribe to the sixth, seventh and eighth...