Sigma 4

was a branch of the Sigma Program. It specialized in deep-earth drilling. In the early 22nd century, Sigma 4 drills were shipped to the Arctic Circle, in order to assist Sigma 6's digging operations.Bentele, Jack. "Beyond the Brink" (March 5, 2024). Frost Giant Studios. Beyond the Brink.
==References==
Category: Sigma Program branches