Skulduggery watched the area Valdis indicated. There didn't seem to be anything there, but he kept watching, and was eventually rewarded with the shimmer of light curling momentarily through the air before disappearing altogether.

It reminded Skulduggery of the way the yellow light from the dimensional portal of the Faceless Ones flickered, although in that instance the portal was impossible to miss. Here, he likely would have missed it if Valdis hadn't pointed it out. An active portal, almost certainly, but a portal to what? Another dimension, another plane, or another spot on the turtle?

Skulduggery took off without warning and closed the distance down to the portal in seconds, being sure to land far enough away not to accidentally touch it. It was only when he approached on foot that he noticed the circle sketched into the roof underneath the shimmer, surrounded by small symbols which looked familiar, but which Skulduggery couldn't immediately place.

He gestured to them. "Any idea what these mean?"