The hatch above fell closed, plunging the room into the half-darkness, but not before Sanji laid his eyes on Luffy's back, the latter caught off-guard and not moving fast enough to pull his new dry shirt over it.

The lit cigarette hit the floor, throwing glowing specks of cinder in a small circle around it.

"That's '" Sanji spoke breathlessly. "That's a slave brand."

Luffy's guard instantly went up, his expression going flat with practiced blankness. A sudden flare of fear in his dark eyes was forcefully suppressed and replaced by deadly sharpness with an underlying caution. His body shifted ever so slightly, muscles tense and ready, conveying intense mistrust, wariness, and apprehension without even saying a word.

Sanji, for his part, didn't notice yet; his mind was still struggling to fully comprehend what he had just stated aloud.

Luffy's voice, low and as cold as ice, sliced through the suffocating silence: "How do you know?"