Tom Devlin is a key figure in the world of graphic novels. His career mimics the evolution of the genre. As founder of Highwater Books, a publishing house he set up in the early 2000s, he treated alternative comics audiences in North America to their first book-length exposure to future star cartoonist/authors John Porcellino, Marc Bell, Ron Rege Jr., Brian Ralph and others - many of whom subsequently joined him at Drawn and Quarterly, the Montreal-based publishing house founded by Chris Oliveros. Tom now works at D&Q as executive editor (and co-owner) alongside his wife, publisher Peggy Burns. His early work - its high production values, thoughtful design and 'bookshelf-ready' formats, plus experience earned as a comics retailer and distributor - presaged, one could say, an explosion in the popularity of graphic novels, one that was amply fueled by the impressive stuff he put out with various artists over the years at D&Q.    I talk with Tom about his early love of comics, his work in comic book stores and his experiences publishing graphic novels; about his life with cartoonists and his work helping to build D&Q, plus the struggle experienced by the medium itself to be taken seriously. Drawn and Quarterly: Twenty Five Years of Contemporary Cartooning, Comics, and Graphic Novels serves as our guide.    We met underneath the well-walked wooden floors of La Petite Librairie D+Q, the company's children's retail bookstore outlet in the Mile End district of Montreal.