Watch the first trailer for 'Batkid Begins: The Wish Heard Around the World'

SAN FRANCISCO (KGO) -- Batkid is back and set to appear on the big screen. The new trailer for the documentary Batkid Begins: The Wish Heard Around the World made its online debut Thursday.

The documentary opens next month in select cities before Warner Brothers releases it nationwide in July.

It's the story of Miles Scott, a Northern California boy with leukemia who was able to live out his wish to be Batkid thanks to the Make-A-Wish Foundation, which turned San Francisco into Gotham City for a day.

That day brought people in the Bay Area together for a good cause, with thousands pouring into the streets in a show of support.

PHOTOS: Batkid plays hero for a day in San Francisco

Click here for information on how to make a child's wish come true.