Barry Allen’s Dad
We’ve seen him in a couple of previous cameos in BvS and Suicide Squad, but this is our first proper chance to get to know Ezra Miller’s Barry Allen. As such, Justice League has to give a summarized version of his background. It’s briefly referenced that he was struck by lightning but, most of all, we get to know the situation with his dad and his career.
We meet Barry as he goes to see his father Henry Allen (Billy Crudup) in jail. He’s been imprisoned for the murder of his wife Nora when Barry was just a boy. Pursuing an interest in criminal justice, Barry believes that his dad is innocent and is dedicated to getting Henry free. Anyone who’s watched The Flash will know that Barry’s right – it’s the Reverse-Flash, his nemesis, who killed his mother.
This should be crucial information for the upcoming Flashpoint film. In the comics storyline, Barry Allen decides to go back in time to save his mom. In doing so, he creates an alternate timeline in which the world has gone to seed (including Bruce being killed as a boy and Thomas Wayne becoming Batman).