He broke into comics in 2011 with Petrograd, written by Philip Gelatt and published by Oni Press, and in 2012 he won the Russ Manning Most Promising Newcomer Award.
: Hell on Earth, Harrow County, which he co-created with Cullen Bunn, and his solo comic book series The Lonesome Hunters.
"[2] In 2008, showed his portfolio to James Lucas Jones at Oni Press, which led to Crook working on Petrograd with Phil Gelatt.
was his third major comics work, due to the accelerated timeline, it was the first to be published, debuting in July 2011 with Petrograd and The Sixth Gun #14 coming out the following month.
In the July 2014 announcement, Bunn spoke about how he'd been wanting to work on a big project with Crook for a long time, but he'd always been too busy.