One Piece Chapter 5.3, page 4-7: The Pirate King and the Great Swordsman

Coby weeps on the ground, fearing he will die. Zoro, still tied to the post, tells Coby to run for his life. Zoro insists he only needs to survive for a month to be freed, but Coby reveals the truth: Helmeppo never intended to keep his promise and plans to execute Zoro in three days.

Coby explains that Luffy punched Helmeppo on Zoro's behalf because Helmeppo was toying with him. Zoro is stunned by the revelation. Coby begs Zoro to help rescue Luffy once freed, promising they can escape the town together if they join forces.

Marines surround Zoro and Coby, aiming their rifles to execute them for betraying Captain Morgan. Meanwhile, Luffy bursts into Helmeppo's room and successfully locates Zoro's katanas.

Luffy finds three katanas and wonders which one belongs to Zoro. Looking out the window, he notices the commotion at the execution grounds. Outside, Captain Morgan orders his men to surround the base and prevent Luffy's escape.