From the Escapist website:
1991. Two years before the events of 5 Days A Stranger. The eccentric British cat burglar Trilby is at large in an American city, robbing the rich to give to himself. Distrustful of his fellow man and patiently skilled in every aspect of burglary, Trilby is on an ongoing quest to scare the ignorant rich by hitting them where it hurts - their wallets. But will his arrogance cause him to bite off more than he can chew?
In The Art Of Theft, the player controls Trilby in a 2D stealth adventure as he embarks upon a number of daring high-profile heists in various outposts of wealth and power across Chapow City. With an arsenal of thief skills at his disposal, he must lift the trinkets and valuables of the idle rich while making as little fuss as possible.