It is pitch black. You are likely to be eaten by a Grue.

The Grue sensor is defined in a library so that applications can use it.

First up is the sensor type. This is the interface for sensors that report on your likelihood of being eaten by a Grue. Such sensors are very important to adventurers, particularly if they are going into dark places as this is where Grues live.

The interface is a simple one. It provides only 1 piece of information, your chance of being eaten. For the details on how this is property should be interpreted please see the documentation in gruesensor.cpp.