Lemnos Fire is a magical, glowing red substance that first originated in the forges of Hephaestus. In the The Quest for Buford, Leo Valdez uses it, along with water from the River Styx, to power the Argo II. If the mixing is not carefully controlled, the result is an explosion similar to the detonation of a nuclear bomb. When Buford runs off with the Syncopator (which is used to control this magical reaction), Leo claims that the forest where Bunker 9 is located will turn into a one, square mile crater.
- Lemnos Fire appears to be named after the Island Lemnos where Hephaestus had a forge.