There's an asteroid on course for a near approach of Earth. Both NASA and a conglomerate of Brazilian, Russian and Indian space agencies send crews out to be the first to land on an interstellar objects.
Both crews learn quickly that all is not as it seems. The asteroid (named "Keanu") may not be merely an asteroid. And it may contain things, familiar things, that no one could ever have expected.
Authors David Goyer and Michael Cassutt are both screenwriters and it shows in the writing. This book is very much an action movie on paper.