Raffles is visited by his old school chum, Bunny Manders, who has fallen on hard times. Penniless himself, Raffles comes up with a scheme to pay off Bunny's gambling debt by getting the money from the most obvious source--a plot that launches the duo into a life of crime.
Brash and crude, Reuben Rosenthall is a real "rough diamond:" a self-made millionaire who wears his wealth in the most ostentatious way possible. In other words, he's an irresistible target for Raffles, if not for the more hesitant Bunny. But as the friends find out, Rosenthall has a trick or two up his own sleeve.
Bunny feels he needs to do more to justify his share of their ill-gotten gains, so the brothers in crime plan a job in which he takes the lead. But when things don't quite go as expected--leaving the partners in a tight corner--Raffles has to take charge to get them out.
Raffles and Bunny swipe the famous Royal Gold Cup from the British Museum, but a group of criminologists track them down, suspecting Raffles of the theft. The gentleman thief is forced to come up with an ingenious way to prove them wrong.
After depositing his precious (and, naturally, stolen) silverware in a bank vault, Raffles departs for Scotland sans Bunny. With Raffles gone, Inspector Mackenzie sees his chance to finally bring the thieves to justice. Everything changes, however, when the bank vault is burgled and Raffles unexpectedly returns to London.
A display of jewelry at the Italian embassy proves too great a temptation for Raffles and Bunny. And so does the chance to rescue a beautiful young maid at the mercy of the evil ambassador. Raffles hatches a plan to steal both, but underestimates the lengths to which the diplomat will go to get his revenge.
Raffles relies on cunning rather than strength to take on a loudmouthed American boxer. Rich from his successes in the ring, the heavyweight champion brags he can catch anyone who tries to steal his gold and silver trophies. Only Bunny's intervention proves him wrong.
London's other gentleman thief has Raffles worried--the city isn't big enough for both of them. Raffles and Bunny track the man down to steal some of his booty. The crook is no pushover, though, and when it comes to ruthlessness, he's more than a match for Raffles.
Plans to rob a Dutch millionaire's home hit a snag when Raffles has to travel to play cricket for England. Bunny sets out to do the job himself, keen to prove his own abilities. However, things don't go exactly as planned--especially when he encounters another thief trying to pull off the same job.
When one of his cricket friends runs afoul of a ruthless moneylender, Raffles decides to pay the man's bill . . . and then some. He also agrees to take on a job for the moneylender. But when the man tries to double-cross him, Raffles decides to execute summary justice.
Raffles takes it personally when the secretary for Home Affairs threatens draconian new measures for offenses against property. He is determined to hit the pompous cabinet minister exactly where it hurts. However, a slip-up by Bunny puts them both within the grasp of Inspector Mackenzie.
For reasons of state, the government asks Raffles to steal a priceless black pearl belonging to the German kaiser--aided and abetted by none other than Mackenzie of the Yard. Complications arise, however, when it becomes clear that Raffles has his own plans for the pearl.
While burgling a house, Raffles gets caught red-handed by a former lover trapped in a loveless marriage. The woman seems ready to leave and start a new life with her old flame. Raffles, worried for his freedom, goes to extreme measures to extricate himself.