We built something, used an old neural sleight-of-hand trick. Coil a very cold wire and a pleasantly warm one in intricate twists. Neither temperature is harmful, but the brain doesn't know how to parse the different signals in such proximity, and assumes something must be wrong.

It's a very...formless sort of pain, visceral and inescapable.

[It was awful, and also exactly what he needed. Physically hurting himself would only have prompted the symbiant to consume him further, leaving Zane's feelings untouched.]