Sai looked off in the direction Usopp had pointed. Back the way they'd come? Not that it mattered. An entry from the other side would be far preferable to this one. They knew there was danger beyond this door. If the ninja had been with those he considered more capable fighters, he might have risked it. As it stood, he saw himself having to cover their way through... if he could.

"That's good," he said, smiling at the pirate. "We should get going, if that's the case." One could never tell when the shift would just abruptly come to an end, after all.