Divided into three 72-page chapters, each a self-contained narrative to avoid frustrating cliff-hanger delays between episodes, it takes place in three distinct eras, building to an apocalyptic conclusion occurring in the present, twenty-first, century.

Allan Quatermain and Mina Murray (who have both become immortal after bathing in the Fire of Youth) continue to work for the British Government as part of the League of Extraordinary Gentlemen, along with new members Orlando, Thomas Carnacki and A.J.

Carnacki has frequent visions of an upcoming disaster where many people will die, and a cult plotting the creation of a "Moonchild" destined to initiate Armageddon.

At Kings Cross, Mina and Raffles meet time traveller Andrew Norton, but he offers little help and speaks almost entirely in riddles referencing events in the far future.

Elsewhere, Janni is mistreated by the staff and guests of the hotel, but when Ishmael appears with news of Nemo's death, she still refuses to join the Nautilus crew and demands he leave.

Distraught and eager for revenge, she decides to fulfil Nemo's dying wishes and fires a flare to summon the Nautilus, which is docked nearby.

As MacHeath sings his final plea from the gallows, the Nautilus (now painted black and with Nemo's skull nailed to the forecastle) emerges from the Thames and destroys every building on the waterfront.

When they arrive, Orlando fends off the pirates with Excalibur, and amidst the chaos Mina runs into Janni, who recognises her from her previous visit to Lincoln Island in 1898.

Mina berates the League for their reckless actions, and as they leave the ruined docks, MacHeath and Suky sing an altered version of What Keeps Mankind Alive?

Mina, Orlando and Allan no longer work for the British Government and have spent the years since the events of The Black Dossier away from Britain, but the sorcerer Prospero summons them back to investigate Basil's murder.

The Nautilus drops the League off at the White Cliffs of Dover, and returning to London they settle into their new base underneath a nightclub (which Mina had planned to use as the headquarters for a superhero team she tried to assemble in 1964).

When Norton does appear, he continues to speak almost exclusively in cryptic riddles referencing works of fiction and events in the future, but he does reveal Haddo's spirit has been transferring into other bodies for years, including Karswell Trelawney and Kosmo Gallion, and directs the League's investigation towards a nightclub called the Flying Cylinder.

From Julia's information, Mina learns that Haddo's spirit plans to transfer from Gallion to Terner at the concert, and she, Orlando and Allan go to Hyde Park to stop the ritual.

Her spirit leaves her body and fights Haddo on the astral plane, but he overpowers her and reveals the League's interference will not affect the planned birth of the Antichrist.

When Norton reappears at King's Cross, he guides Mina and Orlando through the hidden Platform 9 3/4, where they find the wreckage of a magical train full of decaying corpses.

As a baby, the Antichrist (who is heavily implied to be Harry Potter but never referred to by name) was scarred with the mark of the beast on his forehead, and throughout the child's adolescence, Oliver Haddo tried to manipulate him into accepting his destiny by staging a series of adventures set in the school and portraying a nemesis for him to fight.

An enigmatic woman resembling Mary Poppins descends from the sky and destroys the Antichrist by transforming him into a chalk drawing on the road, which washes away in the rain.

Each chapter of Century is accompanied by an episode of a text-story entitled Minions of the Moon, written in the style of a 1960s "new wave" science fiction story.

The next three segments are all set in 1964; Her Long, Adorable Lashes shows Allan in a sexual relationship with the female Orlando, and reveals Orlando to be the true identity of O, the protagonist of Pauline Reage's Story of O. Requiem for a Space-Wizard begins the main story, and shows superhero Captain Universe giving his ally "Vull the Invisible" a tour of his newly acquired headquarters.

In Coming Forth by Day, Mina, the alien "Galley-Wag" and his two Dutch Dolls are summoned to the Blazing World, where Prospero sets them the task of going to the Moon and stopping a civil war between two Lunar races.

They travel to the Moon in an airship called the Rose of Nowhere, and during the journey Mina and the Galley-Wag see the corpse of Professor Moriarty, still clutching the Cavorite engine from the first volume and frozen in a block of ice in orbit around Earth.

Under cover of invisibility, Mina spies on an American Lunar base, where the astronauts speculate and argue about the origins of a colony of giant ants which have been attacking them.

To keep their race alive, the women harvest sperm cells from the frozen body of a human man, whom Mina recognises as Professor Selwyn Cavor.

In A Sea of Crises, Maza orders the Myrmidon army to cease their attack and announces they will return Cavor to the Selenites, because an alternative sperm source has been found.

Maza thanks the crew for their help in saving her race and rewards them with a banquet, but as they celebrate Mina privately regrets this solution and dreads the possible future repercussions.