Colum is a relief worker. He worked for Médecins Sans Frontières and now works for the UK government’s Department for International Development, specialising in humanitarian aid to west Africa. Colum has lived in, and written about, a range of countries including Zambia and Angola. Th eir other joint book is In Quest of Livingstone: a Journey to the Four Fountains, about their retracing of David Livingstone’s last journey