In Assassin's Creed Syndicate it is 1868, and London belongs to one man. Crawford Starrick, Grand Master of the Templars, owns the factories, the railways, the newspapers and the Blighters, the gang that keeps the streets in line. Then the twins Jacob and Evie Frye arrive from Crawley, against their elders' orders. Jacob builds a rival gang, the Rooks, while Evie hunts a Piece of Eden called the Shroud, which Starrick wants for himself. At every stop you hear the game scene first, then the real place and what was really going on there in 1868. It is an unofficial fan walk, not made with or endorsed by Ubisoft, and there are spoilers all the way to the end. The route runs about six kilometers from St Paul's Cathedral to Buckingham Palace, one of our story-driven self-guided walking tours.

Before you set off

The walking alone takes about an hour and twenty-five minutes. With the stories and a few pauses, plan on two and a half to three hours. It is flat almost all the way, with a gentle slope down Ludgate Hill and a long stretch beside the river. Start at St Paul's Underground station on the Central line, a few minutes from the cathedral. You finish by the palace, with Green Park, St James's Park and Victoria stations all within reach. St Paul's charges for entry, so check before you go if you want to see inside. Leicester Square and the palace get crowded at midday. Twice the story steps back in time, at Charing Cross and at Big Ben, and we will tell you when.

St Paul's Cathedral

You're in front of the west steps of St Paul's Cathedral. Look up past the two towers to the great dome behind them. That dome is where our story starts.

In the game this is Sequence 5. Clues left by Edward Kenway, the pirate turned Assassin from an earlier game, send Evie first to the Monument, the column to the Great Fire about a kilometer east of here. She sets a disc at its base, climbs to the top, sets another, and the sculpture up there points her to this cathedral.

She climbs St Paul's, places two more discs behind a statue's base and turns a set of gears. A hatch opens to a hidden room at the very top. Inside is the key to the Shroud's vault, hanging on a necklace. Evie puts it on. Then a voice behind her: "Good day, Miss Frye. I'll take that." It is Lucy Thorne, the Templars' occultist, who believes the Shroud offers eternal life. They fight. Lucy crashes through a window, gripping the necklace and dragging Evie after her. Evie cuts the chain to save herself, and when she looks out, Lucy is gone, and so is the key.

Now the real place. The secret room, Kenway's key and the gear lock are all invented. Old St Paul's burned in the Great Fire of 1666, and the diarist John Evelyn wrote that its stones "flew like grenados." Christopher Wren was chosen to rebuild it. The first service in the new cathedral was held in 1697. In October 1708 the last stone was set on the lantern on top of the dome, by Wren's son, who had been born in the year the building began. Parliament declared the cathedral complete on Christmas Day, 1711. Inside, Wren's epitaph, added by his son, says in translation: "Reader, if you seek a monument, look about you."

Lucy has the key. At the river, you'll hear how Evie took it back. Walk downhill west along Ludgate Hill, turn left at the bottom onto New Bridge Street and follow it to the river, about eight minutes.

Blackfriars Bridge

Blackfriars Bridge across the Thames, with St Paul's behind You're at the north end of Blackfriars Bridge. Face the river and look to your left, downstream. A line of red-painted columns stands in the water there, holding up nothing at all.

In the game the Thames is a borough of its own, run by the Templar Edith Swinebourne, until the twins win it in a gang war. It is also Evie's road to the Tower of London. This is Sequence 6. Henry Green, the twins' fellow Assassin, works out that the key fits a casket owned by the Queen and kept in the Tower. Evie goes in by boat, past Templars dressed as royal guards, and a friendly guard marches her into the White Tower as if she were his prisoner. Lucy turns her back, and Evie kills her with a cane sword. Evie takes back the key and leaves by boat.

In the same sequence Jacob slips into the Bank of England, where the governor, Philip Twopenny, is robbing his own vault for the Templars. Jacob hides behind a painting, and when Twopenny stops to admire it, cuts through the canvas and kills him. "It is their city, not yours," Jacob tells him. Twopenny and Lucy Thorne are both invented.

Now the real bridge, and it is not the one the Fryes knew. The plaque says it was first opened by Queen Victoria on the sixth of November, 1869, a year after the game, on the site of a bridge from the 1760s. Victoria had withdrawn from public life after Prince Albert's death, and Gladstone, her Prime Minister, saw a chance for her to be seen. She tried to pull out more than once, afraid of being booed, and was surprised by how warm the crowds were. Her statue stands at this end of the bridge.

The piers are topped with stone pulpits, a nod to the Black Friars, the Dominicans who gave this place its name. The red columns once carried a Victorian railway bridge for the London, Chatham and Dover Railway. It was taken down in the 1980s, too weak for modern trains, but its columns stayed, and one row of them was built into the widened Blackfriars station in 2012.

Next, the most famous writer in London. Walk west along the Victoria Embankment beside the river to Waterloo Bridge, go up to the road and head north across the Strand into Wellington Street, about eighteen minutes.

Dickens's office, Wellington Street

Find number 26 Wellington Street. A plaque on the wall reads: "This building housed the offices of Charles Dickens' magazine 'All the Year Round' and his private apartments, 1859 to 1870."

In the game Dickens runs into the twins in Whitechapel and signs them up for his Ghost Club. He explains why: "Here we are in the world's most advanced city, yet its citizens are so in thrall to the supernatural they leave themselves vulnerable to charlatans!" These are side stories. The first case is Spring-heeled Jack, a leaping demon who turns out to be a violent cultist in disguise. At 50 Berkeley Square a famous haunting proves to be levers worked by the house's mad owner. The club ends in a pub, toasting its win over superstition, though Evie admits there may be something out there after all. These cases are the game's own.

The real Dickens did work on this street. He ran his magazine Household Words from Wellington Street from 1850, and All the Year Round from this building from 1859, with a flat upstairs. Wellington Street was then the heart of London's publishing trade, home in the 1840s and 1850s to more than twenty newspapers and magazines.

The best story is his rival, G. W. M. Reynolds, who made his name imitating Dickens: Dickens wrote The Pickwick Papers, so Reynolds wrote Pickwick Abroad. By 1850 they were at war in print. Dickens called writers like Reynolds "panders to the basest passions of the lowest natures." Reynolds sneered back that Dickens saw the condition of London's people only dimly. And Reynolds's office was just across the road. The two enemies could have passed each other on the pavement any day.

Next, a theater set on fire. Walk west along Russell Street into Covent Garden's piazza, leave by King Street on the far side, then follow Garrick Street and Cranbourn Street into Leicester Square, about ten minutes.