"Some parts were easy" to condense or cut completely from the Murder on the Rockport Limited novel, says Griffin — such as the part of the podcast where the characters fight a bunch of swamp leeches before even getting to the murder mystery on the train.

"There were certain things I added to the arc to make [the podcast] more game-y. And that's bad storytelling [for a graphic novel], because what were the leeches for? Are the leeches gonna come back and burst through the door? No, they don't come back," he explains. "They're only there because I thought they needed to have a fight before we had five episodes of the boys solving a mystery without any fighting."

But the great thing about recreating Murder on the Rockport Limited for the graphic novel is that the entire story is already complete in podcast form, so the McElroys could go back and clean up the narrative while still keeping in all of their favorite parts.

Explains Griffin: "We now have the benefit of having this omniscient perspective of knowing how everything works out. We don't have to improvise stuff, and our solutions to things don't have to be clumsy. We can take what happened and de-clumsify it in whatever way works and whatever way doesn't completely dismantle this story we told [on the podcast]."