Secret Avengers by Rick Remender Vol. 1

Collects Secret Avengers #21.1 & 22-25. The new era of Secret Avengers begins here! Enter Captain Britain and Giant-Man, as Hawkeye becomes the new leader! But then the Adaptoids strike -- but who are the Descendants? An Avenger will die to find out, as the team literally journeys to the center of the Earth and discovers a city of evolving automatons!