Today we arrive at the last member of the core team in The League of Extraordinary Gentlemen, albeit we should say “last members”: the famous duo Dr. Jekyll & Mr. Hyde. In the movie, they are both portrayed by Jason Flemyng, and, just as all the other characters, they too are made more likable for the general audience, actually ending up enjoying and supporting each other, as they communicate through mirror reflections. Also, Jekyll appears a lot more than he does in the original comicbook, as Hyde is not the dominant personality, but a transformation he more or less controls and uses. Needless to say, in the comics Robert Louis Stevenson‘s best known creature is not so nice and funny, and he’s quite a beast, albeit with something similar to a human heart somewhere. Let’s see together.
Not much is known about Doctor Henry Jekyll‘s life before the experiment that changed his life forever. Born and raised in London, he was a doctor and a scientist fully devoted to Victorian Age morality, but he found great distress in feeling in himself impulses and urges that weren’t worthy of a man of his standing. Wanting to get rid of that 
primeval and monstrous part of himself, Jekyll used all his remarkable intellect to create a special formula, that could isolate and destroy all his basic instincts and violent urges… the potion, however, didn’t destroy them, but it created a whole new person who embodied them all: Mister Edward Hyde. Jekyll was indeed pure as an angel, but only if he transformed from time to time in Hyde, a hideous and small man who was completely and utterly evil, lustful and brutal. At first, Jekyll only took his potion as a medicine, but slowly he became addicted to it. The moment he realized that he was starting to turn into Hyde in his sleep, however, he decided to stop assuming his formula… but it was late already: Hyde had become stronger, and he could take Jekyll’s place whenever he wanted. The formula had split the two aspects of the doctor’s personality, but doing so the evil one had no restraint, and the good one had nothing spurring it to be better than what it was: as a result, Jekyll grew smaller and weaker, while Hyde became bigger and stronger, until he was a hulking giant. After the death of some innocents, including Sir Danvers Carew and his good friend Dr. Hastie Lanyon, Jekyll realized that soon he would have turned into Hyde permanently, and he needed to rush his research to find a cure. He feigned his own suicide, and used the news of his “death” to escape to Paris, France, to continue his studies undisturbed… but once there, as he had feared, he became Hyde once again, and didn’t reverse to his original form for a long, long time.
Mr. Hyde quite enjoyed his time in Paris, as this time it was him who controlled Jekyll: he used the scientist’s meek and fragile appearance to approach prostitutes and lure them in his room, and then turned to rape them to death. The man known as Henri l’Anglais couldn’t be suspected of anything, but the local prostitutes started denouncing an 
ape-like monster who was allegedly responsible for their colleagues’ assassination: this claim alerted C. Auguste Dupin, the inspector who had solved years before the murders that took place in Rue Morgue, in fact committed by an ape. Hyde murdered yet another prostitute, Anna Coupeau, and this finally convinced Dupin to accept help from outside, specifically England, as the MI5, who had always kept track of Hyde, had sent some agents to capture him. Oblivious to anything, Jekyll approached another prostitute, and led her to his apartment, where he transformed into Hyde and tried to kill her. The “prostitute”, however, was Mina Murray, and she was backed up by Dupin and Allan Quatermain, who intervened just in time: Dupin shot off one of the monster’s ears, while Quatermain managed to force him to drink a bottle of laudanum, so that Hyde lost his senses and fell out of a window. The crew of the third agent, Captain Nemo, swiftly arrived and brought the dormant beast in a secure room aboard the Nautilus, where Mina could finally make Hyde her offer: on behest of the British Empire, she promised him full pardon for his past crimes, as well as help in finding a cure for his unique condition… a cure meant for separating the two personas, rather than to erasing one of them, of course. With nothing to lose and intrigued by the game, Hyde accepted, and left Jekyll in his place, confused, naked and short an ear, to make the last dealings. Jekyll gladly accepted to help his own country, and followed his teammates in infiltrating the base of the drug lord Fu Manchu… but much to his distress, it became soon clear that the one the team really needed wasn’t him: they wanted Hyde.
Henry Jekyll is a genius scientist and a virtuous man, a honest and impeccable gentleman; Edward Hyde, on the opposite, is a brute bent on satisfying his lower instincts, a lustful beast who rapes, kills, drinks and eats with no remorse nor pity. If Jekyll has his genius mind to put at use, Hyde possesses vast amounts of superhuman strength and agility, an incredible durability and stamina, and heightened senses so keen that he’s able also to “see” Griffin using his sense of smell and his perception of body heat. Nothing is as it looks like, however: as good as Jekyll may be, he is also a coward and an addict, too weak to get rid of his personal drug despite the consequences, and as evil as Hyde appears to be, he’s also fiercely loyal to his allies, and eventually develops quite an affection for Mina, the first person who never looked at him with horror and hatred, possibly because she has met someone who was even worse than him…
Who's Who 