"The signal source is beneath this rock face," Sig said. "About a hundred and fifty meters deep, much shallower than the passage in southern Iceland. The monitoring station's data shows that its frequency matches the North Pole structure, with moderate amplitude and steady output."
Harry crouched beside the rock face, took off his glove, and pressed his palm against the stone.
He closed his eyes and sensed it for a while. Vibrations rose through his palm, their frequency and period matching those at the North Pole, their amplitude moderate but stable.
Within the nested high-frequency components was a pulse sequence similar in encoding style to the North Pole's, but shorter, with longer intervals, like some simplified version of the code.
"The signal matches the North Pole's, but the code is shorter," he told Isabelle as he stood up. "It seems to be a simplified version of the North Pole's code. This might be an intermediate node formed as the North Pole structure extended southward, responsible for relaying signals from the North Pole to southern Iceland."
"Then is it connected to the passage in southern Iceland?" Isabelle asked.
Harry pressed his palm against the rock face again. This time, he expanded his perception, trying to distinguish the signal's distribution and direction across the island. The vibrations were strongest near the rock face and gradually weakened toward the island's edges. He checked the eastern and northern sides of the island separately and found that the signal was slightly stronger toward the east and slightly weaker toward the north.
"The signal is slightly stronger toward the east," he said as he stood up. "If it relays signals southward, that easterly direction might connect to a node in eastern Iceland. The northerly direction might be the route to the North Pole."
"Then we need