How Get to the Star of Shamash in Cthulhu: The Cosmic Abyss

The first few chapters challenged your mind, but Chapter 5: The Citadel will test your ability to survive. You’ll find yourself in a dangerous place that feels more like a living thing than just old ruins.

![A communication scheme leverages a beamsplitter channel-where Bob receives a signal with transmittance η and an eavesdropper, Willie, receives [latex]1-\eta[/latex]-and enforces covertness by ensuring Willie’s observations are statistically indistinguishable from thermal noise.](https://arxiv.org/html/2604.13116v1/x1.png)

