Tony Harris and B. Clay Moore's "JSA Liberty Files: The Whistling Skull" returns to stores tomorrow as a trade paperback, and CBR has an exclusive look at some of the bonus material fans will be treated to when they pick up their copies. Specifically, DC Comics has provided us with the series' original pitch and character bios, accompanied by art by Harris.

"[This] all came about when it was announced they were going to close WildStorm," Harris told CBR of the offbeat series' origins in a 2012 interview. "I suddenly thought, 'Now, what? Where's my book going to end up?' Literally just one afternoon, it hit me -- like a bolt of lightning. This universe is not that different from 'The Liberty File.' I always hoped and intended to come back to that stuff eventually. I thought about and came up with folding these two worlds together and ran it up the flagpole to see what DC thought about it. I put together a page or two about how it would work ,and Jim Lee, Hank Kanalz and Ben Abernathy loved it. Clay thought it was crazy, but loved it nonetheless."

Check out the bonus material below, and hit your local comic shop tomorrow for your copy of "JSA Liberty Files: The Whistling Skull."