Title: Metaconcert
First published: January 13, 1989
Description: From the back cover:

INTERVENTION

All over the world, the metapsychics are honing their skills, learning to stretch their incredible minds far beyond the ken of ordinary humans.  Most are dedicated to the harmony of the human soul.  But some have darker intentions...

If the metapsychics succeed in uniting Earth's minds to take the next step up in human evolution, a place awaits humanity among the alien species of the fabulous Galactic Milieu.  But if evil minds prevail in their bid for power, Earth will be cut off... and mankind forever doomed!