Chapter 665

The Silver Compass rested quietly on the surface of the sealing layer for a while before its needle began to sway slowly.

The movement was slight, but its rhythm was clear: from due south to east-southeast, then back to due south, over and over again.

A faint purple halo began to emerge around the compass's outer ring, so weak it resembled light reflecting off the edge of a thin mist. Only by staring at it continuously could one barely make it out.

"Deep purple magical residue has formed some kind of long-lasting imprint on the sealing layer's surface," Cassandra said. "Even though the operator has already left, the magic they left behind is still continuously affecting the surrounding environment. Where it comes into contact with the Confederation's silver-white sealing layer, it produces a weak repulsive reaction. That reaction will take some time to fade."

"How long?" Harry asked.

"That depends on the concentration and frequency of the deep purple magic." Cassandra retrieved the Silver Compass. "The Silver Compass's readings show that the residue's concentration is slowly decreasing, but very gradually. It may take weeks or even months to dissipate completely."

Vivi looked at the section of sealing layer at the bottom of the depression. Once the Silver Compass had been moved away, there was no longer any visible sign of anything unusual—only the silver-white sheen, glowing softly beneath the light.

If not for Cassandra's readings just now, she would never have been able to tell that anyone had been here.

"After completing the reinforcement work, the Confederation Technical Group should have kept a detailed survey record of the sealing layer," she said. "If we can obtain that record and compare it with its current condition, we can determine precisely which areas of the sealing layer's surface were touched."

"Kingsley should