Micky O'Neill tries to revive the fortunes of his Liverpool nightclub by promising his patrons he will present a performance by the legendary Irish tenor Josef Locke. After a series of unfortunate bookings (including Franc Cinatra, a Sinatra impersonator), Micky books the mysterious Mr. X, a man who insists he cannot be booked as Joe Locke due to the legal issues that would invariably ensue. The elusive Locke left the United Kingdom during the 1950s to avoid paying taxes, leaving behind "a beauty queen, a Jaguar sportscar, and a pedigree dalmatian, all of them pining". O'Neill's personal and professional life are left in ruin after beauty queen Cathleen Doyle exposes his Mr. X as a fraud. O'Neill returns to Ireland to find the true Josef Locke and bring him back.