herder claas blank was serving 10 years for "insulting a dutch citizen" and rijkhaart, was a dutch sailor convicted of committing "unnatural acts" with another man. the two men initially hostile form a secret relationship, using trips to a private water-tank to bond. the two prisoners on robben island who were later executed for sodomy in 1735 by drowning, after jealousy of other inmates caused problems. their relationship also had a racial component, as jacobsz was a white dutchman, while blank was a black khoi. the film also stars shaun smyth as virgil niven, a scottish botanist who befriends blank for his knowledge of south african flora, including the protea but may in fact have his own sexual interest in blank.