Ultimate Comics Hawkeye by Jonathan Hickman

Collects Ultimate Comics Hawkeye #1-4:

Armed and dangerous, what Hawkeye discovers will revererate across the entire Ultimate Universe. Tasked on a covert and dangerous mission, Hawkeye finds himself in the middle of an international arms race -- but on the brink of obtaining a serum that will change the course of mutant history, has the eagle-eyed hero aimed too high to succeed?