Well, when I decided the I needed Superman/Batman in my life, I went to my LCS down the street and got 51, 52, 53 and 55. 54 I guess was either sold out, or like Madman Atomic Comics 12, just never made it to that one. I'll try again when I pick up 56, otherwise I'll have to check one of the other stores (neither of which are as good as the one down the street).