The truth about what happened to the beautiful Lady Jane Douglas in Paris in 1748 has never been established. Did she give birth to twin boys in a bug-infested boarding house, or did she buy her two sons from poor French peasants to ensure that the distinguished line of Douglas survived in Scotland? The exploration of this 18th century mystery took place in public over twenty years, culminating in a dramatic session in the House of Lords. Combining, as it did, issues of sex, power, money, politics, and aristocracy, 'the Douglas Cause' was a fertile source of gossip and tittle-tattle. Karl Sabbagh gets as near as anyone ever will to the truth, in a definitive account of a case which divided the chattering classes at every level from the burgers of Edinburgh to the English Royal Family.