Role in the film
Lau Xing is first seen robbing the Bank of England. He manages to escape by breaking through the window with a couch and land safely on the ground along with the Jade Buddha he had stolen, which was stolen from his village in Lanzhou, China by a female Chinese warlord named General Fang and her minions known as the Black Scorpions. In a tailor's carriage, Lau Xing manages to change his clothes and remove his fake moustache and beard disguise to evade the police trying to catch him.
Lau Xing manages to give the police the slip when hiding on top of a tree of the garden of a brilliant English inventor/scientist named Phileas Fogg. Lau Xing takes a sudden interest and curiousity to Phileas Fogg's inventions around the garden. When Phileas Fogg states to his French valet, Jean-Michel (whom he mistakenly calls Pierre) that they "will make history or die trying to break the 50 mph speed barrier without organ disruptation" through his experiments, Jean-Michel resigns; stating that he refuses to be catapulted, electrocuted, or have his organs disrupted any longer and refers to his former master as "a very sick man."
When Mr. Fogg rhetorically asks himself "if there is no man brave enough to be his valet," his prayer is answered when Lau Xing accidentally slips from the tree and drops on the ground next to Fogg. Lau Xing finally takes the opportunity of being Mr. Fogg's new valet as an advantage to evade the police authorities. However, Mr. Fogg only accepts French valets so Lau Xing begins persuading him that he is French from his "French" father's side and that his mother's Chinese and "never shuts up." When Mr. Fogg finally accepts Lau Xing and asks him if he's willing to take the risk of breaking the 50 mph speed barrier, Lau Xing agrees as long as it means avoiding the police.
The experiment finally works and is a success until it breaks; causing Lau Xing to fly around London under steam pressure. After accidentally causing some trouble around the streets of London, the pressure runs out of steam and Lau Xing is able to walk again. Lau Xing then tries to resign from being Mr. Fogg's valet, despite being considered a brave valet to whom Mr. Fogg can test with all his other inventions, but then changes his mind when seeing the police arrive.
A few days later, Lau Xing is brought into Mr. Fogg's home and laboratory as he is shown all kinds of his inventions; including bottled light (light bulbs considered undiscovered science from an American named Thomas Edison) that turns on with a whistle. When Fogg asks for Lau Xing's name, Lau Xing dubs himself a French name, "Passepartout."
The next morning, "Passepartout" writes a message to deliver to his father about finding the fastest way back to China to make their village safe once again by returning their stolen most sacred object, the Jade Buddha.
Next, Passepartout and Fogg head out to the Royal Academy of Science where Mr. Fogg announces to all the ministers and lords of science; including his arch-nemesis; Lord Kelvin about the success of his early experiment. However, Fogg is insulted by them, who believes that everything worth discovering has already been discovered. During a discussion, Phileas is pressured into a bet to see whether he can travel around the world in 80 days. If he wins, he will become Minister of Science in Lord Kelvin's place rather than being paid 10,000 pounds but if not, he will be forced to destroy his own lab and never invent anything again. Understanding that the journey will take them to China, Passepartout sees this as an opportunity to travel faster and return home to protect it from his enemies.
At first, Phileas feels uncomfortable about his early decision of accepting the wager but Passepartout, being an honest and caring man, encourages him other wise. Phileas and Passepartout start their journey around the world with steam-powered carriage of Phileas' invention. They borrow a Police carriage and leave London after a confrontation with Inspector Fix, a corrupt officer hired by the Royal Academy of Science to stop them for "violating the city's new vehicle code."
On the second day of the journey, Passepartout and Phileas journey to Paris. Pretending to take Phileas to a science convention with Thomas Edison when seeing Black Scorpions sent by General Fang to retrieve the Jade Buddha and disguised as types of French citizens, Passepartout leads him to an art school where Phileas meets Monique LaRoche, a would-be impressionist. Fang had previously given the Jade Buddha to Kelvin in exchange for military assistance in China. There, Passepartout is attacked by the disguised Black Scorpions, whom he manages to defeat countless times victoriously. When Monique learns of Phileas' ambition, she convinces them to take her with them. They depart in a hot-air balloon, chased by Fang's warriors and other French citizens.
Whilst on the Orient Express of Munich, Monique learns that Passepartout is trying to return the Jade Buddha back to his village and is travelling with Phileas to get there quickly. Monique keeps his secret in exchange for him convincing Phileas to let her travel with him. Despite Passpepartout's failed attempt to convince Fogg otherwise, Monique manages to get herself accepted when making the train go faster, which Fogg previously failed to do and who had hoped Monique would fail as well.
After Passepartout stops Inspector Fix from arresting him on the train, the trio travel to Turkey, where the train stops in Istanbul on the tenth day of the journey. Guards climb on board and inform the trio that they are greeted by Prince Hapi and invited to his banquet at his palace. During the Prince's banquet, he orders Monique to stay as his seventh wife since he had taken a sudden love interest when he first laid eyes on her while the men are ordered to leave when they find the idea of a seventh wife completely ridiculous. The men blackmail Prince Hapi into releasing Monique using a prized but apparently flimsy "The Thinker" statue of the Prince sculptured by Rodin himself. The statue is accidentally destroyed, much to Hapi's anger, but the three travelers escape from the guards and lock them up inside the palace using the statue's broken right arm.
Back in England, according to Inspector Fix's report, Lord Kelvin learns that Phileas has been involuntarily abetting a thief's escape when Fix states that the bank thief and Fogg's valet are the same man. He orders the British colonial authorities in India to arrest them both.
On the twenty-fourth day in Agra, India, in a train, Passepartout is seen telling Indian children stories about the famous "Ten Tigers of Canton"; including the most famous of them all, Wong Fei-Hung. After a few discussions about opinions of legends between Fogg and the children, the train is stopped by the British military. Passepartout sees notice of the price on his and Fogg's head and warns his companions. Disguised as women, they evade the police but are again attacked by Fang's warriors; hulking chained agent, a female agent, and Inspector Fix. Using Inspector Fix and martial arts (by Passepartout) and a sextant from his cane of many inventions (by Fogg) as weapons, they defeat their assailants and flee to China.
On the forty-eighth day in Lanzhou, China, as Mr. Fogg sleeps in a yak-powered cart, Monique notices Passepartout's troubled look and asks what's wrong. Passepartout states that he can't keep lying and manipulating Mr. Fogg much longer. Monique comforts him when she tells him that it would only cost Fogg's "money" in the wager's loss for that matter but Passepartout justifies that Fogg will lose something much more than that. Finally, they arrive at Passepartout/Lau Xing's village. As they pass by, the villagers begin to welcome, greet, and praise Lau Xing's victorious return as they repeat "Lau Xing" a few times; including some children (who are then told by Lau Xing to give his friends the same greeting too) and of course, Lau Xing's family; especially his mother.
Later, Lau Xing enters Wong Fei-Hung's home and reveals the Jade Buddha to him. Wong welcomes him home and tells him that his brothers(and sister)-in-arms will be proud. When Wong asks if his association with Fogg is wise appropriate and wise, Lau replies that Fogg is the most disciplined man he has ever met. A fact proved otherwise when Fogg clumsily and drunkenly displays some animal fighting movements to villagers and falls down on the ground.