Xu Polu froze for a moment.
Lu Chen did not explain. He pulled a sheet of paper from his robe and handed it to Xu Polu.
On the paper was the formation diagram he had drawn the night before—crooked and uneven, with slanted lines and distorted proportions, yet the position of every single line was marked with perfect clarity.
"Three li outside the city, there are seven earthen mounds," he said. "Beneath them lie bones left behind from an ancient battlefield, where the deathly aura is strongest. Those seven mounds are naturally formed formation nodes. The Spirit-Locking Formation must be set around them. Drive three-inch nails around the mounds and one-inch nails into their tops. Once the formation is complete, the deathly aura will be locked within the mounds and won't flow beyond the city."
Xu Polu stared at the formation diagram for a long while. "How long can this formation hold?"
"That depends on the density of the deathly aura," Lu Chen said. "If that thing doesn't come, it can hold for a month without issue. If it comes—" He paused. "Three days."
"Three days." Xu Polu repeated the words softly.
Lu Chen rose to his feet. "Three days is enough. Within three days, I'll go in and find Dragonblood Grass. If I find it, Tuoba Shan's arm can be saved. If I don't—" He did not continue.
Xu Polu raised his head. "You're going into the ruins?"
Lu Chen did not answer. He lifted the tent flap and walked out.
Outside, it was already fully light.
There were far more people on the drill ground than there had been the previous night. The wounded soldiers had crawled out of their tents and sat in twos and threes in the open, basking in the sun.
None of them looked