Some people, however, working with specially tuned amber, could generate more than the usual amount of psi power and use it in some highly specific ways. Ghost hunters, technically known as dissonance-energy para-resonators, comprised one of those groups of high-powered para-resonators.

The term ghost hunter described quite accurately what most of them did for a living. Their psychic abilities, while certainly impressive, were not what anyone would call multifunctional or flexible skill sets. Career options were limited.

As far as anyone knew, the only practical application of a hunter's talent was in controlling and destroying the highly volatile, potentially lethal balls of fiery, acid-green psi energy formally known as UDEMs. The acronym stood for unstable dissonance energy manifestation. They were known as ghosts because they drifted like so many lost specters through the endless network of underground tunnels that honeycombed the planet. No one knew why the long-vanished aliens had built the catacombs in the first place. The UDEMs were just as much of a mystery.

Most of the experts assumed the ghostly green phantoms had been meant to function, along with the dangerous psychic illusion traps that also infested the tunnels, as some sort of high-tech security system. But, as was the case with all of the ruins, artifacts, and relics left by the vanished race of beings that had first colonized Harmony, the real purpose of the ghosts was a matter of sheer speculation.

One thing was indisputably true, however. The energy ghosts made exploration and excavation of the vast network of underground passages extremely hazardous. And, since exploration and excavation of the catacombs was not only big business but also a major focus of several private and government-funded labs and many academic institutions, the ability to destroy ghosts guaranteed a certain degree of job stability.