What is the main conflict in The League of Extraordinary Gentlemen by Alan Moore?

Faced with an apparent weapon of mass destruction, British intelligence recruits a quintet of individuals with extraordinary ability to seek out and neutralize the menace. The assembled league of extraordinary gentlemen, ironically led by a young woman, recovers the essential component of the weapon only to discover they have been double-crossed by British intelligence, which plans to use the component in a weapon of their own. The league intervenes once again and saves the day.