“I’ll swallow anything as long as it’s illegal!”

We’re pushing it with this one, as anyone who’s seen it will know… but every so often, for completism’s sake, we have to wander off the road and onto the moors. What’s that sign up ahead? “Diversion – British folk tales (via funky 70s setting)”? What do we think, my fellow travellers? Ah, sod it… I’m a bit fed up of the main road, let’s try the scenic route.

And scenic Tam Lin is… if director Roddie McDowall (yes, that one) isn’t parading beautiful people in front of the lens, then said beautiful people are roaring past in an assortment of stunning cars. Certainly, from a “horror starlet” point of view, we’re probably looking at an unmatched cast here – Stephanie Beacham, Joanna Lumley, Madeline Smith and Jenny Hanley are all there (somewhere), flouncing about in kaftans and big floppy hats in a very 1970 way.

Now I’d better add at the beginning here that I have no idea which version I saw for this review, and so don’t know how close it was to the director’s original vision. A quick Google informs me this film had a troubled release and was eventually re-cut by the studio, hence no bugger having heard of it beyond people like you, dear reader.

But it has to be said that beyond the many delights it holds for the middle-aged Brit horror fan, Tam Lin is a bit dull – taking its time to tell quite a slight story of jealousy and betrayal (McDowall: “Not my fault – monkey bastard hands!”).

Mickey (Ava Gardner – yes, that one) is the matriarch leader of a group of hip young things who spend their time driving from one end of the country to the other along the then-brand-new motorways, apparently completely employed in lounging around and looking sexy.

Mickey has a favourite among her young following – Tom (Ian McShane, insert joke about him collecting antiques here if you must).

“I love you,” he tells her as they lounge in bed during the film’s prologue. “I’m immensely old,” she replies.

“Doesn’t matter…. The older you get, the more beautiful you become.”

The team go north, and we’re informed via a portentious voiceover that the ballad of Tam Lin concerns a young man held in thrall to the queen of the fairies (aha).

Tom isn’t Mickey’s first young lover, and it appears that the previous one has fallen out of favour somehow. Meanwhile Tom is doing his best to follow his predecessor in the pissing-off-Mickey stakes by developing an immediate crush on Janet (Stephanie Beacham), the innocent daughter of the local vicar.

Janet herself is quite taken with the lifestyle she sees in Mickey’s home, and we see it through her eyes, in all its soft-focus chocolate advert glory. Who wouldn’t want to swap a career as a door-to-door puppy seller for a more glamorous life as drunk frisbee champion, or just to indulge in carefree evenings of cigarette-and-spacehopper parlour games (hey, it was the 70s)?

Tom is prepared to give all these high-jinks up, however, as he falls for Janet’s more buttoned-up charms. Even some not-so-veiled warnings from Mickey’s “private secretary and accountant” Elroy (Richard Wattis) about what fate befell Tom’s predecessors (usually violent death) can dissuade the young buck from taking up with the vicar’s daughter.

Mickey is wise to the relationship (“I can taste her on you. She tastes like watered milk”) and when Janet announces she is pregnant by Tom and runs away to Edinburgh to have an abortion, Tom has a week to find and stop her before Mickey hunts him down and kills him (her words).

It has taken a lot of fannying about and nicely framed shots of the English countryside to get to it, but we finally get to some vaguely horror shenanigans now, as Tom, who has found and stopped Janet, is himself found by Elroy and his goons, beaten up and dragged back to Mickey, who has a new entourage (and indeed a new Tom). For the evening’s entertainment the spacehoppers are replaced by a somewhat literate game of “murder”, as a drugged-up Tom finds himself attacked by Mickey’s “creatures”, after she informs him “if they catch you, they’ll tear you to pieces”.

As of writing, “folk horror” is a big deal again on these islands, but for a long time it was a strange blip in our cinematic history, with a handful of films coming out over a couple of years in the late 60s and early 70s and then vanishing. It feels like people hungry for more were falling over themselves to include oddities like The Ballad Of Tam Lin in this mini genre, but this is no Wicker Man.

It is, however, strangely beguiling. Gardner is great as the forlorn/vengeful Mickey, and although not the most exciting of stories, it looks brilliant. Never conceived as a horror film, distributors American International recut it and gave it the name “The Devil’s Widow”… which explains why it doesn’t make much sense as a horror film.