Vivi stuffed the parchment into the inner pocket of her robe and jerked her head toward the end of the corridor.
Harry followed at her right side, turned slightly sideways, and the two of them advanced soundlessly along the concrete wall.
A row of old storage lockers was set into the left wall of the corridor. Their doors had all been pried open, and in one locker on the lowest level, three spare guidance Rune Plates were stacked neatly.
Vivi crouched and quickly checked the Rune Plates' material and etching marks. The craftsmanship on this batch of Rune Plates was exactly the same as the detachable device in the iron cabinet in the basement of the Salem house. They had come from the same hands.
She stuck a Micro Tracking Rune to the outside of the storage locker, then continued forward.
At the end of the corridor, it turned left into the final straight passage before the Main Control Room. The walls here were no longer bare concrete, but black-gray stone slabs reinforced with spells by The Ashwinder Party. A low-power warning rune was embedded every two meters in the slabs, its red light casting a regular alternation of brightness and shadow down the corridor.
At the entrance to the Main Control Room, they could hear people speaking softly inside—two voices, one male and one female.
The man's voice was hoarse, his speech very fast, as if he was assigning tasks or reporting the situation. The woman's voice cut in occasionally, each time with only one or two words, her tone clipped.
Mixed in with them was another voice, as if transmitted through some kind of remote communication device, carrying obvious electronic interference noise.
Vivi raised the Portable Magic Fluctuation Monitor and aimed it at the crack in the Main