Meanwhile, in the lower-middle levels, inside an abandoned laboratory from a bygone era.
Usopp, Nami, and Chopper were trapped on the other side of an alloy partition.
After a frantic series of attempts and some teamwork, they finally used Usopp's specially made "Drill Star" ammunition,
combined with the pounding blows of Chopper's Arm Point, to bore a narrow tunnel steadily deeper into the thick alloy partition.
"If Usopp hadn't wasted so many chances earlier, we wouldn't still be digging this tunnel."
Usopp offered no argument when he heard Nami's complaint.
After all, he had wasted plenty of their already limited supply of "Drill Star" ammunition trying to guess which door was right.
"Keep going, Chopper! Just a little farther! I think there's a breeze on the other side!"
Nami urged him on, gathering a faint current of air around her Clima-Tact as she tried to sense the end of the tunnel.
Chopper shifted into his Human-Beast Form, his two hooves becoming a pair of heavy hammers.
He alternated powerful blows against the metal wall softened and broken open by the "Drill Stars," producing dull booms.
Debris flew as the tunnel slowly widened and extended.
But just as they seemed about to break through, with Chopper ready to deliver the final blow...
"Wait!! Stop!!"
Usopp suddenly cried out in alarm, his face turning sheet-white in an instant.
His body began trembling violently, and beads of cold sweat formed on his forehead.
His eyes, usually tinged with exaggeration and timidity, were now wide as saucers.
"Usopp?" Nami immediately stopped what she was doing.
Perceptive as she was, she immediately realized something was wrong.
Usopp's Observation Haki was the most sensitive among their companions, even allowing him a degree of "X-ray vision."
Seeing him like this, Nami's heart leaped into her throat. "What...