When small-time accountant Lionel Ellerman takes on what should be just a routine investigation, he uncovers illegal offshore holding companies, leading to a large firm of City accountants and, in time, to the Mafia. Lionel is abducted to Naples, where d'Amico (Ivano Staccioli), the boss of bosses, suspects him of planning to sabotage the Mafia's attempts to infiltrate the City of London. It all looks very black for Lionel, but by sorting out the boss's books, he might just get himself a second chance.