To fuel such a fever long.

Does what it says in the title, however the tone is less flippant than that.

Nami has an extremely uncomfortable reaction to an island's pollen, and Zoro offers to help.

The fight is brief and unsatisfying. The whole thing takes no more than five minutes and no more than two swords. They still hum for blood as Zoro sheathes them and faces the gang's growling, pissed off boss. “Fine,” the man shouts. “We’ll take you then, huh? Plenty of folks will pay to bring a big man down low,” he says nonsensically. “What—” A sharp pain in his ankle cuts him off. A downed man pulls a needle out of Zoro's skin.