The Prestige

In 1890s London, Robert Angier and Alfred Borden work as shills for a magician under the mentorship of John Cutter, an engineer who designs stage magic. During a water tank trick, Angier's wife Julia fails to escape and drowns. Angier, devastated, accuses Borden of using a riskier knot, causing her death. When Angier asks Borden which knot he used, Borden claims not to know. The two become bitter enemies.