Adventurer Fred Ward is sentenced to hard labour for horse theft, escapes, and becomes a bushranger under the name of Captain Thunderbolt. Stealing mainly from squatters, he quickly becomes notorious. Trooper Mannix is assigned to capture him dead or alive, eventually trapping him. After a long gun-fight, Mannix finds he has killed Thunderbolt's friend Alan Blake, and that Thunderbolt has escaped. Mannix passes off Blake's body as Thunderbolt's but the legend persists that Thunderbolt still roams free.