Spoilers. Batman Annual #25, wherein we FINALLY discover the means by which Jason Todd return. And, thankfully, Winick is writing, so not only is the story good, it matches up with the Red Hood arc perfectly. In any case, the short version is that Jason comes back as a result of Superboy Prime doing some reality tampering, setting things right. One of these tamperings involves a reality where Jason survives the Joker's beating and the explosion. I suppose he adjusts the normal reality...with that one? In any case, Batman never knew Jason escaped his grave because all the detection traps were made to prevent people breaking INTO Jason's coffin, not OUT of it. Jason had some brain damage for awhile, came out of a coma, lived via instinct on the street, til he was discovered and handed over to Ra's al Ghul, who tried to rehabilitate him to no avail. Talia, doing what she believed was right, shoved Jason into a Lazarus pit, against her father's wishes. It restored Jason's mind and body completely, and he is as you see him now. He escaped Ra's' fury, and was set up with all the documentation he needed through Talia. He finds out that Bruce let the Joker live, and through some mechanism (the Lazarus pits, feeling betrayed/disappointed), he snaps. He does his stint as Hush to see if Bruce will show remorse, and when he doesn't, it's the final straw that leads to the Red Hood, and what follows after that. Overall, I was really impressed. I had low expectations for this comic (I mean, come on. It's an annual.), but Winick actually pulled it off pretty damn well.