Near the coast of Denmark, Fortinbras's army marches toward Poland. He sends a captain to Elsinore with a message of greeting for the King of Denmark.
By sending the captain to greet Claudius, Fortinbras shows he means to keep his word not to attack Denmark.
The captain runs into Hamlet, Rosencrantz, and Guildenstern, and happily tells them the land about to be fought over is worthless. Hamlet asks Rosencrantz and Guildenstern to go on ahead. In a soliloquy, he bitterly compares himself to Fortinbras and his soldiers. They go to die just for a chance at honor, while he, with much greater reason to act, has failed to revenge himself on Claudius. Hamlet vows "from this day forward may all my thoughts be bloody," and promises to focus only on revenge.
Fortinbras is willing to act to gain honor. Though Hamlet, as you'd expect, sees such thoughtless action as ridiculous, he also sees the nobility in it.