Patronimo's Apache tribe is still waging war against the white settlers. The damage on both sides is getting heavier and heavier, and Lucky Luke is called in to restore the peace between Patronimo's tribe and Colonel O'Nollan.

But while negotiating with both sides, Lucky Luke is perceived as a traitor, and only a wild twist of fate will enable him to come out of this tricky situation unscathed. Can Lucky Luke mediate between the two parties and still be trusted by both sides?