Search - Across the Sea of Suns (Galactic Center, Bk 2)

Across the Sea of Suns is a 1984 hard science fiction novel by Gregory Benford. It is the second novel in his Galactic Center Saga, and continues to follow the scientist Nigel Walmsley, who encountered a machine extraterrestrial in the previous book, In the Ocean of Night aboard an expeditionary spaceflight to find other life. Eventually Nigel discovers evidence of the major conflict in the galaxy.

Good sci-fi

I haven't read this, but my husband did. He enjoyed the series very much. I have all 6 books if you want the whole series at once.