From the start, the two men were under intensive surveillance in the first joint counter- IRA operation involving MI5 and the police.
Almost every move made by Hugh Jack, 37, and Robert Fryers, 44, was observed by anti-terrorist officers.
But even without the detailed knowledge of the two men's actions, which led to Fryers being caught red-handed on a street in London with a "napalm-style" bomb containing Semtex explosive in his bag, the men were always less than professional.
In one comical episode, Fryers was waiting to pick up a Ford Escort at the Scratchwood services on the M1 near London, which was packed with seven blocks of Semtex, seven detonators and seven timing devices. While staying at a Trust House Forte hotel in South Mimms, Hertfordshire, he got drunk, chatted up various women from a works outing, and ended the evening by singing a selection of Irish ballads.
"He was the star of the show," said one of the detectives involved in the case.
Anti-terrorist officers believe the apparent poor quality of the IRA recruits reflected the terrorist organisation's shortage of suitable operatives following a series of arrests and prosecutions.
The men, however, were identified and followed because of Fryers' contact with a known group of IRA members who were already under surveillance. Fryers, who worked as a bouncer at a Belfast nightclub, was known within the IRA as a hard man and was used as an "enforcer" to maintain order and respect within the community. Nicknamed "The Fat Man" by his MI5 watchers, he had three previous convictions for minor crimes. The father of three, who is separated from his wife, came to Britain in the summer of 1993.
In June, anti-terrorist officers followed Fryers to Jack's home at a council flat in the new town of Sauchie, near Alloa in central Scotland.
Jack, who was an IRA sympathiser related by marriage to a convicted IRA terrorist, had about 30 convictions for minor offences such as assault. He acted as Fryers' runner, hiring a garage near his flat and a unit at a Glasgow industrial centre which was used for storing bomb-making equipment.
On 8 July, Fryers travelled to London, where he collected the Ford Escort packed with explosives. A team of officers from MI5 and the Central Scotland, Strathclyde and Metropolitan police forces, watched Fryers empty the car into the hired garage, makingenough noise to wake the neighbours. Fryers also bought bomb-making equipment, such as batteries, from Woolworth's in Stirling.
The bomb-making equipment was later taken into the flat, where the incendiary bomb was made using one of the 2.5 kilograms of Semtex and a milk bottle filled with petrol.
On 13 July, Fryers drove to London with the bomb. But the journey became a farce as he had to stop the car repeatedly to fill it with oil and water because of engine leaks. The following morning, while waiting to catch a bus in north-west London, armed officers ambushed and arrested him.
Detectives believe Fryers had targeted the City of London and intended to penetrate the "ring of steel" security. His bomb, which would have ignited into a fireball, may have been intended for a City pub. The two planned six more bomb attacks and security sources believe the cities targeted included Birmingham, Manchester and Newcastle.
Jack discovered Fryers had been arrested while watching the lunchtime news. He immediately hid the remaining bomb-making equipment in dense woodland, but it was discovered after an intensive search by the police and army.