Having made a huge sum from his deal with the oil company, Jack is mixing in London high society. He is asked by his land agent to help him broker the sale of an expensive necklace to Morty, Jack's old American colleague, on behalf of wealthy Philip Martin, with a commission for them both. Martin's sister Jane takes a shine to Jack but proves to be an unbalanced psychiatric case. The sale goes ahead and when Jack learns that Morty paid off the mobsters who were threatening him he waives his half of the price.