The story from issues #1-4 of the latest Superman-Batman team-up title is collected, along with Justice League 23.1, as Batman/Superman Volume 1: Cross World TP (The New 52)
. This is the story of Clark Kent and Bruce Wayne's first meeting - "years ago" - when Clark goes to Gotham to investigate the murders of some Wayne Enterprises scientists. Later that same night, in Metropolis, Catwoman is up to something, and is caught in the act by Batman, who is quickly caught in the act by Superman (in t-shirt and cape - this is early days). Catwoman is possessed by something, and in the ensuing fight, Superman and Batman and the entity go "BOOM"... and find they are somewhere else, where they meet older versions of themselves... though it is not until issue #4 that we see a caption telling us where they are.
The two younger characters are extremely suspicious of each-other's motives, while the elder two are obviously friends from way back. This volume shows how the old friendship formed, and begins the process of forming the new one, as the possessing entity slowly reveals that it is a scout for a forthcoming interdimensional invasion - the "Boom" being a big hint, and the fifth comic collected here being the major spoiler...
This is an excellent story, showing the differences between the New 52 and the old 52 Superman and Batmen, and explaining why Earth 2 had a tougher time of it than the other Earth when Darkseid attacked. I found the artwork to be a bit too dark and confusing for my liking, as it appeared to obscure the story rather than illuminate it. It would have been more in keeping with the world of the Swamp Thing.
THE SPOILER ZONE
For a detailed breakdown of the individual issues collected here, see Batman/Superman Volume 1: Cross World TP (The New 52)