Force Five is a group of operatives with an unnamed British Intelligence agency.
"Five men, all experts in their own field, made up Force Five, the finest counter-intelligence strike force in the world." That is the explanation we are given shortly after the start of the first recorded adventure. Working for an unnamed and apparently secret department in the British Intelligence community, these men receive their orders from Sir James Morris.
Oddly for an organization in the early 90's with an assortment of ways of getting the word to each member, the manner that Morris uses for alerting the quintet of a mission is to place "the usual ad in the Times" which hopefully they would see some time the next day!
After a time, though, that slow method is drastically altered when one of its members, 'Brains', comes up with the idea of using "a special microchip embedded in a tooth filling. It vibrates when they are needed". This is considerably faster.
The group needs to be summoned because each of the five members has his own day job which pays the bills and keeps each pretty busy. Every member is well respected in that occupation. They only leave those jobs, coming up with plausible reasons for their absences, when they get the word that they are needed. In turn, each member brings to the group for use in the missions his personal area of expertise.
The team consists of:
Barry Martin - "one of the country's top character actors known as 'The Man With A Hundred Faces'. He uses his skills to infiltrate targets, often with virtually no advance notice.
Butch McGraw - a superb athlete playing a back in American football in the British League
'Brains' Tyler - a computer expert who designed and built his on large system.
'Wheels' Rogers - a world-class Formula One race car driver and expert with cars and trucks.
'Greasy' Wilson - a skilled pilot who can handle any flying device that has wings or blades.
Chief nemesis to Force Five initially is Apocalpyse, a criminal/terrorist group out to cause trouble anywhere at any time and, from the looks of their activities, score a profit along the way.
Later that organization seems to have been replaced by Shadow, "the most efficient terrorist organization in the world". That group, based we are told in Holland, becomes very annoyed with Force Five's interference in a scheme and makes destroying them a large priority.