Planet M-113 from orbit.
M-113 is a desolate planet that was once home to an ancient and long dead civilization, as well as the homeworld of an indigenous species known as the M-113 creature or "salt vampire".
The planet was hotter and more arid than Earth, so human inhabitants needed to ingest larger amounts of salt to adjust for the loss of the mineral due to sweating. No salt was found on the planet so it had to be imported. Apart from dry brushes, it was home to a poisonous plant, the Borgia plant, classified as a carbon group 3 vegetation, similar to Earth's nightshade family.
A winged beast.
Several stone sculptures depicting various animals were found on the surface of the planet among vast ruins, including sculptures of a winged creature holding a sword, a small stone sculpture resembling a dolphin as depicted in Earth's Renaissance, a four-legged deer-like creature seated like a traditional Egyptian sphinx statue and a sculpture of a lion-like animal.
In 2261 archaeologist Robert Crater and his wife Nancy began an expedition on M-113 to conduct a survey of the planet's many ruins. They moved into a large deserted ruin on the planet surface and began their archaeological research. During the first four years, they shipped out large amounts of artefacts, gathered from several digging sites on the planet, made numerous reports and were visited by a number of ships. A large drop in shipments was noted in the fifth year, however.
Ruins on M-113.
Unknown at the time of the Crater expedition, a single surviving member of the "salt vampire" race continued to live on the planet. It would eventually kill Nancy and would continue to live along with Robert until 2266. Crater buried his wife on a hill on the planet but was no longer as efficient in his archaeological work, causing the drop in shipments. (TOS: "The Man Trap")
- It is known that the salt vampires are intelligent but it is unclear whether the ruins belong to them, or another sentient species on the planet. At least two humanoid skulls were among the artefacts in Crater's collection.
- According to a non-canon source, The Worlds of the Federation, M-113 is the fourth planet orbiting a star named "UFC 113", and the creatures referred to their world as Fotialla. An earlier non-canon source, the novelization collection Star Trek 1, called this planet Regulus VIII, suggesting that it is in the Regulan system.