Sarge Hawk and Colonel Grimm narrowly escape a Tan attack on their Green base by helicopter. On their way, they spot a suspicious Blue tank in a nearby town, prompting Hawk to investigate. Hawk follows a Blue Spy into an illuminated cave, leading to a vast, gigantic world. The trapped Spy is captured, revealing crucial details about Plastro’s plans, the Portals, weapons, and the Heroes’ whereabouts.
After rescuing Hoover, Riff, Thick, and Shrap, Grimm informs Hawk of Plastro's ultimatum: "Surrender or be destroyed." Hawk must destroy the final portal, located in Fort Plastro's most guarded corner. Following a challenging solo battle, Hawk succeeds and learns that Vikki stayed with Plastro to gain trust and gather information. Teaming up with Scorch, they deliver this intel to the Green army. Returning to Fort Plastro, Hawk launches an attack on the base’s eastern side, advancing his mission to protect the Green Nation.
