Final act in a Falklands drama

From Hull to Exeter is a five-hour cross-country schlep. With each mile, though, Ann Addis's 15-year burden grew lighter. No more cajoling. No more digging. This one-woman detective agency-cum-lobbyist could relax now she was in the hands of the professionals.

On arrival in Exeter, Mrs Addis is greeted by John Evans, Devon and Cornwall's Chief Constable. On the lawn of his headquarters he poses for an impromptu photo opportunity. Mr Evans is endorsing a mission by a team of his detectives bound for the Falkland Islands on Thursday to probe the death of Mrs Addis's son, Alan, who died while serving as a Royal Marine on the islands before the war. Mr Evans and Mrs Addis, 53, sporting her gold jewellery and a nut-brown Californian tan, look incongruous together. But over the years she has been party to many unlikely scenes - sleuthing among the islands' farmers and peering from the pages of Penguin News - in attempts to resolve 19-year-old Alan's death.

Long before the Argentinian invasion burned the South Atlantic outpost on to the British psyche, the Marine was part of a small detachment training islanders against possible invasion. He disappeared. One winter's Friday night, 8 August 1980, he and two colleagues went to meet three others after a week's stint in the remote North Arm settlement on East Falkland. They spent the evening drinking with 40 locals in the functional hall that doubled as a social club. It wasn't a boozy affair.

Towards the evening's end, the comrades left in ones and twos for parties in nearby houses. No one is sure who left last, but Alan was last seen at 1.30am. The little steamer, MV Forrest, where the Marines spent the night, cast off at 7am, only to notice Alan's absence and turn back. Despite countless lurid rumours about his fate, no trace of him has been discovered.

Even this sketchy account, full of gaps, took a long time to emerge. But two police constables were at the door of Mrs Addis's Hull home within hours, saying her son had fallen overboard and drowned. In the coming days, the story lurched from one explanation to another. He wandered off inland. Got lost on patrol. Slipped off a jetty and drowned. None, to Mrs Addis's ears, rang true. The inconsistency only heightened her suspicions.

So, in her grief and confusion, began the seemingly endless campaign to unravel the mystery. "I knew he was gone, but I knew immediately something was not right," she says, her steely, practised composure disintegrating in gentle sobs. "I was angry that no one at the Ministry of Defence could tell me what had happened." The Falkland Islands police, who then had just one full-time constable, weren't up to the task. An inquest recorded an open verdict.

In November the following year, after constantly lobbying her MP and exerting unrelenting pressure on the Army, she got to the islands by military transport. Talking with islanders and to her son's colleagues, she discovered they shared her disquiet and believed the Army should have sent its Special Investigations Branch (SIB).

"In my opinion Alan had been murdered," she says. "I think people know more than they're saying about what happened. As soon as I got back I called the MoD and said I wanted the SIB to go out, otherwise I'd go on the airwaves. They only sent one man for one week. The hardest was when he came back and I couldn't see the report. The officer called me in and said he felt as I did, but didn't know where to turn. I think the Army was embarrassed by the affair and wanted me to go away."

The Argentinian invasion a few months later in early 1982 hampered things further, when Alan's case files were destroyed. It is unclear whether the islanders did this, to prevent Marine files falling into enemy hands, or the Argentinians, in a furious bout of wanton destruction as the British forces approached Port Stanley. In 1983, Mrs Addis, a divorcee, tried to commit suicide. "I felt I'd failed Alan. I was still distressed at losing him and frustrated with the MoD. It was like a brick wall."

To escape from the destructive, vicious circle she went to California. She relinquished her Hull car parts business and set up a second home near San Francisco. "I just had to survive and put something back in there," she says, pointing to her heart. "I knew I was ill, an illness borne of frustration. The only way was a total change."

Still Mrs Addis didn't give up her quest, year in, year out, badgering the authorities. Rumours about Alan's death haunted her. A particularly poignant one reached her in 1993, telling of a pub boast that someone had got away with his murder. She alerted the now rebuilt Royal Falkland Islands Police, who were able to scotch the rumour; six months earlier they had started to reinvestigate the troubling case.

Saloon-bar talk among the 2,500 inhabitants of the islands - a "Dartmoor without trees" where serious crime is virtually unknown - still turns to Alan's death. "It's still a topic of conversation," says Superintendent Ken Greenland, Chief Constable of the island's 17-strong force. "That's something I find quite unusual. Certainly in North Arm it's a subject of some morbid fascination. They, plainly, would like the matter resolved. And from our point of view as police force it affects our professional conscience and it's something we'd like cleared up."

But after two years' investigation the force's expertise was exhausted. As, last March, Mrs Addis made the 8,000-mile journey once again, the force passed the file to Devon and Cornwall, which "inherits islands" and had trained some Falklands officers. "For my own part," says Supt Greenland, "I have no doubt that he died as a result of foul play, or perhaps fatal accident, and the body was buried."

The favoured theory is that Alan Addis got into a row with locals and was "cold-bloodedly "murdered, his body burned and the remains buried. Substantiating that will fall to Detective Chief Inspector Bob Pennington and his team of three detectives who are flying to the Falklands. The officers, apart from sifting the physical evidence, will conduct a "couple of crucial interviews" with people thought to know more than they admit. "We are going down to put the screws on some unknown locals we believe are responsible," said a police source. "We need a confession."

To intensify pressure on this "closed community" and encourage someone to break ranks, Mrs Addis made an emotional three-and-half-minute video. It was broadcast world-wide on Forces satellite television on the 15th anniversary of Alan's death and is now being screened in the Falklands. Staring plaintively to camera, she says: "Those of you who are mothers will know what I mean. To wake every morning with that terrible feeling of loss in the pit of your stomach. Sometimes the ache is unbearable."

Buoyed by British and Falklands' police confidence, Mrs Addis, who no longer talks to the MoD because she feels they let her and Alan down, believes her "private nightmare" will soon be over. "All I want is to bring back Alan's remains. I know they may only be burnings. The police have told me that. But it's part of me. I want him laid to rest. I'd also like justice, for Alan and myself. But if it's between justice or Alan's remains, I'd choose the latter. Is that too much for a mother to ask?"