Infernal engine

This page contains spoilers for the following products: A Song of Silver.
You can disable this banner in your personal preferences. An infernal engine is a special magic circle derived from Thassilonian designs that immobilizes and siphons the life energy from outsiders to power magical devices and structures. Such an engine can be identified by the circle's traits and lines of runes. They are expensive and difficult to create and can take months to craft, and require the summoning or binding of an outsider.

Deactivation

An infernal engine is difficult, though not impossible, to manually deactivate and reactivate without killing the outsider within it. It can also be made inert through the use of spells or other effects that generate areas of antimagic. Attempting and failing to deactivate an infernal engine causes a violent reaction of fire and unholy energy.

To destroy an engine, one must destroy the stone into which it is infused.