Back in 2013, Make A Wish transformed San Francisco into Gotham City for a little five-year-old Leukaemia patient, Miles Scott.

The story inspired thousands and little Miles became known as ‘Batkid’, the boy who saved the day. Now, Warner Bros has made a documentary about it called Batkid Begins.

The documentary offers an in depth look at the event and how it came to be.

The trailer’s just been released, check out it.

Apparently, there’s a Batkid Begins film in development too, it’s said to star Julia Roberts.