It began with a cryptic note to my ‘contact.’ It read: Call this number at precisely 07.03am. Thereafter the number will cease to exist. At the appointed time, the call came. “Scotch on the Rocks?” I whispered.

“This isn’t a pub. It’s the BBC,” was the reply.

“Aren’t they one and the same?”

A pause.

“Need a programme,” I persevered. “No problem, mate. Which one?” the voice answered.

“Scotch on the Rocks.”

“That is a problem…” Click.

I understood. Scotch on the Rocks, remains the Holy Grail of political drama. When it aired, 50 years ago, it caused such a stushie it’s never been repeated. Hardly surprising, since it linked aspirations for independence with the fictional Scottish Liberation Army – a depiction which raised the ire of SNP leader Gordon Wilson. Complaints bombarded the BBC.

It was based on a novel co-written by Douglas Hurd – then a Tory backbench MP. This did nothing to dispel suspicions of ideological bias. I once came tantalisingly close to a viewing. As a student I drank with Dominic Behan. I called him “Supreme Behan” – a sobriquet he pretended to dislike.

“Domo’, one of the best songwriters of the last century, was employed by Strathclyde Region to mentor wannabe scribblers. During what’s euphemistically called, “a session,” I broached the rumour of his bootleg recording. “You’ve more chance of seeing Lord Lucan riding Shergar in the Scotia Bar,” was his response.

He believed Scotch on the Rocks to be so appallingly crass, he no longer gave it house room. In tracking the political thriller down, I’ve tried to debunk pervasive myths. It has spawned more conspiracy theories than Lee Harvey Oswald’s passport. No, all episodes were not wiped by the BBC. Yes, only three episodes now exist. Episode 2 and 3 have vanished like a politician’s promise.

Myth is the unavoidable result of having no access to a subject, but much blank paper to fill, or pub punditry to dispense. Myth can also cause misunderstanding. My neighbour ‘Darcy’ saw two suited men, wearing sunglasses, tampering with doorhandles around my abode. He mistook them for scientologists. Was it related to my endeavours?

One last option remained. Actor John Cairney, now 93, played the part of a Marxist MP in the terminally elusive programme. Publicity shots show JC sporting a Bobby Kennedy haircut, his finger jabbing the air. Through an emissary, JC told me, “I’ll do what I can, kid.”

Last week…On a wet night in Glasgow. A car pulls up inside an underground car park. Engine shuts off. Footsteps reverberate. A hooded figure strides from the dark. “Code?” he asks.

“Sorry?” I say.

“Code? When King Charles heard Ellynora sing the national anthem. He said?”

“Oh, yeah. What Have They Done to My Song, Ma?” An unmarked manila envelope is proffered. The hood scuttles away.

Finally, history is in my hands. A half century of intrigue, knowing nods and winks, and the fable is tangible. The verdict? Well, if you disregard plot, as the writer certainly did, pantomime characters abound. A Wendy Wood caricature veers toward comic farce. An actor, renowned for playing villainous roles, is ideally cast as a Tory grandee.

Did I say plot? Well…John Cairney's character, later revealed as a Soviet stooge, joins forces with Glasgow gangs seeking ‘adventure.’ They team up with a renegade colonel, complete with handlebar moustache. The result, if not the intention, is absurd.

Each episode is entitled: Phase – indicating the military adventurism of the protagonists. Phase 4 opens in Blackpool. Appropriately enough, as, so far, it’s been end of pier stuff.

The Secretary of State for Scotland is dumped in the sea, wrapped in a saltire. This isn’t comical, but chilling. I can conceive of no circumstances, in Scotland, in which such an atrocity would be conceived, let alone carried out. By Phase 5, they’ve taken to the glens to overthrow the established order. The battle scenes owe less to Sam Peckinpah and more to The Benny Hill Show. I half-expected to see Hill’s Angels run over the mountains to that show’s theme tune, Yakety Sax.

Female representation is risible, with a femme fatale swooning over John Cairney’s revolutionary ardour. Her characterisation does not extend to permitting her views of her own. Any need to remind you that, in 1973, Winnie Ewing was the foremost proponent of Scottish autonomy? With the formidable Margo Macdonald waiting in the wings.

Modern programming is blamed for shrinking the national brain. Not true. It began long before spivs despoiled TV's terrain. This farrago proves it.

The legacy of Scotch on the Rocks is this: No serious Scottish political drama has been attempted since. Chastised by protest, Scottish channels retreated to unadulterated dross like River City.