The vast deserts of Outback Australia hold many secrets, but there is one great mystery which stands out among all others the mystery of the lost Leichhardt expedition. In April 1848 Ludwig Leichhardt and six other men set out westward from the Queensland frontier, heading for Swan River settlement in Western Australia. They never arrived. Somewhere in the immensity of the Outback, then almost completely unknown to Europeans, the entire expedition disappeared. For more than 160 years supposed clues to the fate of the expedition have been discovered human skeletons, old guns and rock paintings, Aboriginal stories of white men being massacred or perishing of thirst, trees marked L or old wagon tracks beyond the frontier. Official and private expeditions have followed up leads, but nothing conclusive has been found. This book draws together and summarises all the search expeditions, assesses the validity of all the claimed Leichhardt relics and the various theories proposed all the attempts to answer the perplexing question, "Where is Dr Leichhardt?".