In an alternate 1899, several high profile crimes occur in various nations throughout Europe, each allegedly carried out by nationals of other countries, leading Europe to the brink of war.
An emissary of the British government, Sanderson Reed, arrives in a gentlemen’s club in Kenya, hoping to recruit the legendary, but now aged, hunter and adventurer Allan Quatermain to investigate the situation.
However, Reed finds that Quatermain's sense of patriotism has declined over the years, and he refuses to offer his services. Suddenly, a group of armoured men armed with machine guns appear, and begin killing the club members. Quatermain defeats the attackers single-handed, giving chase to finish the last one, thereby surviving the club's destruction by a bomb planted by the men. Quatermain reluctantly agrees to return to England, deciding that a full scale war between the nations of Europe will quickly spread to Africa.
Some time later, Quatermain arrives in London and meets the mysterious 'M', who explains his plan to assemble a League of Extraordinary Gentlemen to combat the threat of The Fantom, who is the true mastermind of the current crisis, and ensure world peace, by stopping him from destroying Venice. In short order, Quartermain meets Captain Nemo, the invisible gentleman thief Rodney Skinner, and Mrs. Mina Harker, whom 'M' introduces as a well-regarded chemical scientist. Skinner had stolen an invisibility formula from its creator and is now helping the government in return for an antidote.