看似平静的湖面，暗藏杀机潜伏深渊。青铜剑属于几级文物

　　Childhood friends Tommy and Tuppence meet in London after having served in World War I. Recently "demobed", short of money, and with no job prospects, they decide to become adventurers for hire. Soon, they are employed by the British Government to locate a secret treaty signed before the war.