I'm nosing around a grubby backstreet in Bristol, in southwest England, when I finally come upon the faded object of my desire: Applied to the side of a pub, near a pair of pungent garbage bags, it's a small stencilled image of two kids skipping across a road - each carrying an automatic weapon.
This twisted take on childhood should be enough to identify its creator. But in case there's any doubt, a blockish signature, or tag, has also been applied. Even if you know little about graffiti, you've probably heard that Banksy - a born-and-bred Bristolian with a penchant for combining whimsy, satire and anti-authoritarianism - is the world's most famous street artist.
Banksy has generated as much controversy as kudos in recent years. He painted "We're bored of fish" in giant letters inside the London Zoo's penguin enclosure. He's stencilled ladders and windows on Israel's West Bank barrier, And just this week he managed to paint a three-storey mural with the words "One Nation Under CCTV" on the side of a London post office - right under the nose of one of those ubiquitous closed-circuit security cameras.
But for all the hype, Banksy's identity remains a closely guarded secret. Rumour has it that he's in his 30s and his real name is Robert Banks. The only thing known for sure is that he hails from Bristol. While the historic dockyard city hasn't officially embraced him as a tourist attraction - not everyone is happy celebrating illegal activity - the town is like his own open-air art gallery.
With little idea of where to look first, however, I meet with Steve Wright, an arts editor and the author of Banksy's Bristol: Home Sweet Home, a guidebook to the artist and his work. He happily fills me in on the local lad who made good - all the while ducking questions about Banksy's identity and how well he might know him.
Wright says that "Banksy's done more than anyone to push graffiti into being seen as an art form," citing his international success and regular coverage in mainstream media. But he has never forgotten his roots.
"Although Banksy's famous now and hangs out more in London," he says, "he's still sharp and thought-provoking - and he still creates new works around Bristol."
Suggesting I should think like a graffiti artist and head down the side streets, Wright recommends exploring Stokes Croft and Easton, working-class neighbourhoods not far from the city centre.
After locating the kids-with-guns work on the side of the Full Moon pub, I easily spot one of Banksy's iconic works on Stokes Croft Road. Mild Mild West recalls a 1980 street riot in the area that was triggered by a bungled police raid. It depicts a teddy bear throwing a Molotov cocktail at a phalanx of shielded policemen, and Wright's book describes it as an alternative "Welcome to Bristol" sign.
Continuing on the same thoroughfare until it becomes Cheltenham Road, I nip down a side street called Bath Buildings and find the Old England pub. Completely covering a parking lot wall is Take the Money and Run, one of Banksy's earliest surviving works. A collaboration with other artists, it's a kaleidoscopic abstract of swirling colours, stylized lettering and mysterious running figures.
Next up, Park Street offers an easy-to-find and somewhat whimsical Banksy. Quickly applied behind a temporary construction hoarding, the large untitled piece depicts a naked man hanging by his fingertips while his chagrined lover and her quizzical husband stand in the window above.A few minutes later, I come across the artist's most recent Bristol work. Overlooking a hospital on Perry Road, it shows a police marksman pointing his gun at the street - while a child stands behind him, ready to burst a paper bag.
