With a chilling cold open, in which a companion calls out in desperation for the Doctor’s help, it is clear that we are in for a terrifying time as the latest Big Finish Colin Baker Doctor Who trilogy concludes.

Travelling in the company of Phillipa ‘Flip’ Ramon, nee Jackson (Lisa Greenwood) and Leading Wren Mrs Constance Clarke (Miranda Raison), the Doctor detects temporal interference and the trio find themselves at a remote caravan park in the 1980s. So remote that it does not even have electricity and boasts but a single payphone.

The time-travellers are not the only visitors though, as Andy and Joanna have just checked in; a young couple taking some time to “work things out” in their relationship in the wake of a family tragedy some twelve months previously.

Their welcome from site manager Perry Till is less than friendly, as the old man insists that portable televisions, radios and cassette recorders are all strictly forbidden. He does seem to know the Doctor though, and has a clearly uncomfortable reaction to Constance… while she recognises the name of the place: Abbey Marston.

Those familiar with the work of Jonathan Morris will expect his tale to be clever, as he is adept at delivering impressive temporal twists and turns. In addition, the tone is downright dark and scary taking its cues from horror movies and running with an initial hook which wouldn’t seem out of place in the Moffat era. Exploring it with the luxury of time afforded to an eighties four-parter, we progress through emotional trauma and moral implications before progressing to a more sci-fi solution.

There are some comic nice touches throughout too, from Andy’s pretence that the pair are married as they are out in the country, to the British wartime ingenuity which has adapted and harnessed the temporal situation to their advantage – compete with militaristic jargon to suit. For us though, the finest moment belongs to Flip, with her reference to “tempura interference”.

‘Static’ boasts the legendary David Graham, a multi-generational Anderson collaborator, as its principal guest star. Playing both younger and older aspects of the same character, he offers a tremendous performance which swings through shades of desperation and unlikeability during his complicated journey through the story.

Director Jamie Anderson brings in other, less familiar voices too with Scott Chambers and Pippa Nixon playing the unhappy couple whose tragedy and relationship issues anchor the initial shocking revelation which make for a terrific episode one cliff-hanger. Both their performances are very natural, which amps up the terror no end!

The tone is very much set by the music and sound design, which is by Joe Kraemer & Josh Arakelian. Unsettling from the off, there are haunting sounds, persistent rain and what sound like distorted wind chimes… as well as the ominous ring of a telephone. This might not be one to listen to in the dark!

As this trilogy closes, it is worth saying just how close-knit this TARDIS has become; the relationship between Flip and Constance, which seems to shift from sisterly to comrades-in-arms teasing the Doctor, works so well with Flip’s impetuous nature tempered by Constance’s natural reserve, while she coaxed out of her shell by the younger woman’s enthusiasm. Both spark off the Sixth Doctor in different ways and it is all thankfully far removed from the spiky and antagonistic companion relationships he endured onscreen in the 1980s.

‘Static’ is the conclusion to a very strong run; from the moral challenges of ‘The Behemoth’, to the futuristic society of ‘The Middle’, which posed questions regarding the treatment of elders, and this tale which grapples with grief and looks at the ethical compromises made in wartime, these seem like a very grown-up, meaty set of stories. Which it not to say they are not fun, as well as being both challenging and thought-provoking. While all the attention may on the high profile box-set releases, it is clear there is plenty happening the monthly range that is worthy of praise.