Waller (the fat lady President) got Bruce's DNA to make sure their would be a Batman in the future. She arranged for it to be injected into Warren McGuinness, which ultimately led to Terry's birth. Then she wanted to recreate the same tragedy that Bruce went through for Terry, so she hired the Phantasm to kill his parents, but she chose not to. But Terry's dad ended up dying anyways, and soon after that Terry met Bruce Wayne, which led to him becoming Batman. And that's pretty much his origin. I just don't see why they even bothered making this. It kind of tainted the Batman Beyond character for me.