Joshua Viola has good reason to be excited for Denver Pop Culture Con this weekend. “I sold more books there than I ever thought I would,” the 36-year-old said of the convention formerly known as Denver Comic Con. “We sold out of everything we brought last year and left the show early.” Viola, the founder of Denver-based Hex Publishers, and author Warren Hammond have a new sci-fi book to push — “Denver Moon: The Saint of Mars,” a noir-ish, co-authored sequel to 2017’s “Denver Moon: The Minds of Mars” — and plenty of anthologies, graphic novels, young-adult books, soundtracks, T-shirts and other Hex product to sell. Kevin Mohatt, Special to The Denver PostWarren Hammond, left, and Joshua Viola stand before a wall of movie props and memorabilia Viola has collected over the years at his house in Westminster on Monday, May 20, 2019. But despite his success over the last five years, Viola is using the May 31-June 2 convention to bring an end to Hex.