The Shimmer by David Morrell

Police Officer Dan Page, mystified by his wife's (Tori) disappearance, traces her to a small cattle town, Rostov, Texas where a mystical phenomenon appears after dark. These luminous vari-colored balls of light hover and seem to emit a strange humming sound. When a madman cuts down twenty people with an AK47, Dan offers to help investigate these unusual goings on. Morrell again writes a compelling mystery, complete with human emotions and how the lights seem to affect those humans. Good read. Sandy Penton