Creatures of the forge. Heat-lovers. Smiths.

Intake core temperature: 40.2 °C. Flagged as fever. Antipyretics did nothing. Across fourteen months, independent of ambient temperature, metabolic demand, or pharmacological intervention, the value held at 40.2 ± 0.1. The Soviet conclusion: not pyrexia. Baseline. A thermophilic vertebrate. No known surface multicellular animal lives there as a set-point. Microbial thermophiles do, in vents and hot springs. This metabolism is built for geothermal habitat, not for weather.

Myocardial thickness approximately three times human norm. A pulmonary system that can run aerobic and anaerobic. A hepatic organ of unfamiliar morphology. The 40.2-degree set-point is the key that unlocks the rest: enzymes tuned to a temperature that would be a medical emergency in a human and a working condition beside a siphon tapping the upper mantle. The forge in the folklore is not a metaphor for industry. It is the organism's preferred room temperature.