To not burden their impoverished parents, two siblings decide to share a pair of shoes after the brother loses the sister's. While this turns out to be more difficult than they imagined but fate offers a chance in the form of a marathon.
The crooks in London know how it works. No one carries guns and no one resists the police. Then a new gang appears that go one better. They dress as police and steal from the crooks. This upset's the natural order of the police/criminal relationship and the police and the crooks join forces to catch the IPOs (Impersonating Police Officers), including an armored car robbery in which the police must help the gangs to set a trap.
