Sudden Explosion

John left the room, holding an object in his hand. He studied it for a moment, looking at the runes carved into the formation disk he held. It was circular, with glowing blue formation runes, the complexity of the runes beyond his ability to read what they did. 

Furi had given him the formation disk, which he said was a location formation disk. It allowed Furi to know the location of whoever held it, so long as they were within a certain range of him. Furi had mentioned his mistake of not supplying his children with such an object before, and would not make the same mistake again. 

With John's importance to Furi going forward, he seemed unwilling to risk John's safety. John studied the disk for a moment and then put it away in his spatial ring, which allowed Furi to detect it. If he had placed it in his palace realm, it would have become undetectable, which defeated the purpose of the object.