It is the 1880s. Tom and Marie Flint have moved to New Mexico and run a thriving cattle business. Then, in El Jango, two fleeing bank robbers murder Flint's elder son when they hold up the Santa Fe stage. The killers, intent on revenge for past events, call themselves The Regulators. They want to destroy the Flint family. Up against the so-called Regulators, Tom and his younger son Jason fight a desperate battle to the death. But whose death?