Liver crystal

The internal components of Clockwork Cherubs included a liver crystal.

As part of an experiment with invisibility devices, the members of the Department of Problem-Solving had their livers retuned to “vibrate in synchrony”, such that the “crystalline organs” now allowed any one of his Problem-Solvers to feel the presence of any of the others nearby. They ended up maintaining the modifications thereafter, which was technically against the rules. (PROSE: Lord Thymon and the Department of Problem-Solving)