Jesse L. Martin isn't just a great actor β€” he's also an accomplished singer and writer. And he's teamed up with three other Flash actors, Carlos "Cisco" Valdes, Rick "Eddie Thawne" Cosnett, and Patrick "Captain Singh" Sabongui, to make The Letter Carrier, a short musical film about a black family in 1860 hiding in the mountains and telling scary stories.

Well, apparently Joss Whedon pledged "outstanding amount" to the Kickstarter and, in thanks, Martin, Valdes, and Cosnett sang a beautiful gospel cover of the Firefly theme song, "The Ballad of Serenity":