Back home I sacrifice myself to save Al. Instead of dying I go through the Gate, which is where I apparently stay for two years.

[It wasn't really a choice to leave Al so much as bring him back, but the second decision was the one that Ed had trouble coping with.]

When we're reunited it starts a war between the two worlds, our's and the one I'm trapped in.

I managed to get back home, but in order to stop the war I go back through the portal to break it down from that side. Al followed me through the portal, the one in Purg had already been in Germany before he arrived, but this Al didn't get that far before arriving here instead.

At least that's what I've heard.