Jason Tripitikas (MICHAEL ANGARANO) is a normal teen growing up in South Boston and fan of all martial arts films. His favorite thing is looking for the latest titles in the Lu Yan Pawn Shop run by the elderly Old Hop (JACKIE CHAN) where he also finds an ancient staff.
Yet, his obsession with such fighting hasn't transferred to the real world, meaning he must put up with being physically intimidated by the likes of Lupo (MORGAN BENOIT) and his gang of bullies. That comes to a head when they force Jason to escort them to the pawn shop where Lupo ends up shooting Old Hop who tells Jason he must deliver that staff to its owner.
Not knowing what that means, he flees, with Lupo and his thugs in hot pursuit, and ends up falling off a roof. When he comes to, he finds to his shock that he's in ancient China, surrounded by armed soldiers. Even more surprising is that a middle-aged warrior, Lu Yan (JACKIE CHAN), manages to save him despite being intoxicated, and then informs Jason of the history of the mystic staff.
It seems that it once belonged to the Monkey King (JET LI), a mischievously playful but formidable warrior who was tricked by the Jade Warlord (COLLIN CHOU) during a battle. As a result, the Monkey King was turned into a stone statue, but not before sending his staff off into the distance.
Now, 500 years later, the Jade Warlord is preparing to allow the witch Ni Chang (BING BING LI) to join him in immortality, but not before she returns the staff to him. He's not alone in desiring it, however, as The Silent Monk, a.k.a. Lan Cae He (JET LI), has long been searching for it. Accordingly, he soon joins Jason and Lu Yan on their quest, as does a young woman by the name of Golden Sparrow (YIFEI LIU) who wants to avenge her parents' deaths at the hands of Jade Warlord's men.
From that point on, the unlikely quartet tries to return the staff to the Monkey King, all while contending with the Jade Warlord, Ni Chang, and a host of warriors who all want to catch and stop them.