Summertide

Summertide (1990) is a science fiction novel by Charles Sheffield written within the Heritage Universe. The story takes place millennia in the future, with humans having extensively colonized our spiral arm of the Milky Way and having encounted a number of intelligent alien races. Littered throughout the galaxy are hundreds of massive abandoned engineering projects built by a mysterious race, referred to as The Builders, extinct for 3 million years. An eclectic group of scientists and opportunists are descending upon one such artifact at a time when its surrounding environment is extremely dangerous to study an unusual phenomenon.

The novel is similar in scope to works like Rendezvous with Rama and Ringworld, but showcases more of Sheffield's concentration on eccentric characters and dark psychology. Unlike other followers of the Big Dumb Object school of sci-fi, Sheffield does an excellent job of creating a compelling future world.

Summertide has a sequel, Divergence.