Say what you want about Sanji's captain, but the boy has never told a lie.

He stands there in the orange light of dusk, arms folded, the whole ocean spread out at his back. Small for someone his age, for someone worth his bounty, for all the miracles under his belt.

Sanji looks up at him, at this force of nature that swept into his life and carried him away from everything he knew into a bright, bold new world, and says, "Don't promise me impossible things, captain."

Luffy's scowl deepens. There's a smattering of freckles across his cheeks and the bridge of his nose, dark against his brown skin. In his candy-colored clothes, with that weathered strawhat perched on his head, Luffy's fierce expression might be comical to someone who doesn't know him.

But Sanji knows him.

Since Ace died, since those two grueling years the Strawhats spent apart, Luffy has been a force to be reckoned with when it comes to his precious crew. He takes it personally, more so than he ever has, when one of them comes back to him hurt.

And now, when Totto Land is two days behind them, he looks at Sanji the way he looked at Robin at Enies Lobby, the way he looked at Nami at Arlong Park, the way he looked at Vivi in a sprawling desert – as though Sanji is someone who still needs to be saved.

Nevermind that they escaped Big Mom, foiled the wedding plot, rescued Sanji's former family, got away with only Jimbei to still be accounted for. Nevermind that Sanji came away from this ordeal with more good fortune than he ever could have dreamed.

Luffy looks at him the way he's looked at a dozen other precious people a dozen times before, with such absurd faith it's hard to meet his eyes.

"It's not impossible," the boy retorts. "I said it and I meant it. Are you saying you don't believe me?"

Well, that has never been the problem. Sanji laughs quietly around his cigarette, and then laughs a little more at the offended expression on Luffy's face as a result. "I wouldn't dream of it. But you can't account for everyone in the world who might mean us harm. Whole armies, the world government, other pirates. Ours isn't the safest life to lead. We're bound to get hurt now and then."

And they are. And they've made peace with it. They're here because they want to be, and damn all the warning signs they pass along the way.

But Luffy – who has always maintained "if I have to die for my dream, so be it!" – who looks at his new Wanted, Dead or Alive posters in glee – who thinks of 'safety' as an abstract concept at best – says, "No."

Sanji blinks. "No?"

"No. I'm not gonna let anyone else die. I'm not gonna let any of you go away. I lost you once, because I wasn't strong enough, but I'm strong enough now."

He stands there, nothing more than a speck on the sea, this mighty boy who has moved mountains for his crew. His big brother died in his arms, his crew was scattered across the world, and he spent two years apart from the people he loved most to make sure it would never happen again. He stands there, and he makes a ridiculous promise, and he means it.

"If anyone hurts you, I'll kick their ass," Luffy says boldly, the voice of someone who walked into hell and helped start a war for just one person he loved. "They'll never get away with it. I won't let them."

Ah, Sanji thinks, hiding a smile behind his hand as he takes a pull from his cigarette. So that's what he meant.

"In that case," he says aloud, blowing out a plume of smoke, "consider it a two-way street, captain. I won't let anyone hurt you, either."

It's the right thing to say when Luffy's forbidding expression relents into a shining smile, the whole of him bright beneath a darkening sky. Sanji looks at him and thinks, if Luffy asked it of him, there's nothing he wouldn't do.