The Relic by Douglas Preston and Lincoln Child (1995)

Preston and Child have written a series of gripping thrillers set mostly in New York City in such fascinating locations as the Museum of Natural History and the subway tunnels. In The Relic, a mysterious creature is loose in the New York Museum of Natural History. Quite the page-turner.  The Reliquary is the sequel that is even more page-turning and suspenseful than the original. Should be turned into a movie at once.  One more favorite is Cabinet of Curiosities, where a building excavation in New York City has revealed a late 19th century serial killer's stash of bodies, and now, the murders are beginning again. The authors have wonderful, practically cinematic powers of description. Very entertaining reads.