Catalyst tells the story of the most devastating cyclone in history, striking one of the most overpopulated and defenseless places on earth. On November 12, 1970, a full moon and high tide coincided to create a massive storm that built up a twenty-foot high wall of water surging with deadly force across the low-lying islands in the Bay of Bengal. The islanders, along with their livestock, boats, possessions and any buildings not made of concrete, were flung into the raging wind and sea. Only the strongest survived by clinging for hours to the tops of palm trees. With an estimated half a million deaths, the Great Bhola Cyclone stands as the worst in recorded history. Drawing on original field notes, archival research, recollections of participants, interviews and memoirs, Catalyst tells the true story of a group of young friends' spontaneous response to this unprecedented natural disaster, and to the civil war following in its wake that led to the new nation of Bangladesh. A compelling tale about choices that define us and shape our lives, it illustrates how times of great calamity and confusion can become a cartography of human purpose.