Flash: Who Is Harrison Wells?

"Who Is Harrison Wells" is the nineteenth episode of season one of the live-action superhero fantasy series The Flash and the thirty-first episode of the series overall. It was directed by Ralph Hemecker with a teleplay written by Aaron Helbing and Todd Helbing based on a story treatment by Greg Berlanti and Andrew Kreisberg. It first aired on Wednesday, April 21st, 2015 at 8:00 pm.