Chapter one of One Small Step, the third Y: The Last Man story, collected from issues #11 to #17, written by Brian K. Vaughan and drawn by Pia Guerra with a cover by Jones.
From The Publisher
Yorick Brown is the last man on Earth...but is he the last man in the solar system? That question is raised when a mysterious visitor lands on top of Yorick's speeding train. Plus, the identity of the shadowy informant is finally revealed.