"Kirigakure's intelligence doesn't include that information. We need to find the clues ourselves before we leave."
"Where do we look?" Tenten asked.
Chisen tapped his cane against the next step down and began descending.
Under the dim stairwell light, his shadow stretched long across the wet steps.
"The hospital," he said. "The underground archive at Konoha Hospital.
"Three years ago, I took part in a medical collaboration project sent over by Kirigakure's Anbu. We were studying an abnormal chakra waveform. Its source was an unconscious fisherman found in the waters east of Kirigakure.
"That fisherman's chakra waveform didn't match any known living creature.
"Kirigakure suspected some unknown underwater organism and sent him to Konoha for sample analysis.
"The project was terminated halfway through because, after the fisherman woke up, he remembered nothing, and his chakra waveform returned to normal.
"But the project files are still there-including the raw data for that abnormal waveform."
He stopped at the turn and looked back at the three people above him on the stairs.
His glasses reflected two small squares of light under the dim yellow lamp.
"If that abnormal waveform data resembles the chakra waveform of the vessel on the island, we can identify its weakness before we leave.
"Three days-that's enough."
The entrance to Konoha Hospital's underground archive was on the second basement level of the inpatient building, behind an iron door at the end of the hallway marked "Restricted archive. Authorized entry only."
The iron door was painted dark green. Countless openings and closings had worn the corners down to bare metal. A sign fastened with twisted wire hung from the handle, with "Lighting malfunction. Bring your own flashlight" written on it in marker.
Chisen took out his key and unlocked the door, then reached his cane into the darkness and