Or is there even one? Maybe it's a malfunctioning Synthetic, or some lunatic with Space Depression, or maybe all those things...
or it's been you the whole time!
Page 116 of the Starter Kit. Valerie Reid has a synthetic replacement arm.
- Prosthetics? Never seen some or read about in the alien universe. But they surely will exist in a "nearly-natural-function" version. In case you survive the alien.