Harold stared at the spot. "That's an amazingly thin line," he said. "What's it doing here?"
"Not a lot," said Jasfoup. "Just hanging in space."
"How very odd." Harold walked all the way around it. "It's as if someone used a very fine pen to draw upon the air molecules." He looked down. "It's not even connected to anything. It's just hanging in mid air." He went to touch it but Jasfoup, with reflexes honed from avoiding the whips of his elders in his days as a minor demon, grabbed his wrist.
"Ow!" Harold pulled away. "Why did you do that?"
"Because it's not just a line," said the demon. "It's a fracture. It's be like passing your hand through cheesewire. You know how earthquakes are caused by two tectonic plates push against each other?"
"I do. One continent tries to hump another and all the houses fall like dominoes on a wobbly table."
"Exactly. Well this is a fracture line between planes. Ours has pulled away from another."
"Fascinating. Which plane is the earth pulling away from?"
"Ah! I need something really thin." He summoned an imp. "Devious? Fetch me two palate knives."
Armed with the two thin blades, Jasfoup inserted them into the fracture and prised open the line far enough to see into. A line of bright light fell vertically across his face and he shrieked, letting go of the knives.
A line of skin smoked. "Heaven," he gasped. "The mortal plane is pulling away from Heaven."