The Japanese ambassador is travelling to Washington with an entourage of samurai when his train is ambushed by two ruthless robbers, Link (Charles Bronson) and Gotch (Alain Delon). The thieves steal his money and his priceless samurai sword. But Link is double-crossed when Gotch runs off with both the sword and money.
Soon Link finds himself reluctantly joining forces with the ambassador's samurai bodyguard, Kuroda (Toshiro Mifune). Despite their cultural differences and early resentment, Kuroda and Link pair up to find Gotch. The revengeful duo eventually track him down, only to discover that a vicious twist of events will change their lives forever...