A thoroughly contemporary twist on an old theme: little Irwin, in informal green and a peaked cap, is incessantly bossed by three big elves in suits and bowlers. When Santa forgets one present, it's Irwin who resourcefully harnesses a dog to his small sled and sets off through ``unexplored territory'' (a satisfyingly risky area with chasms, wolves, sharks, and similar amusements), catching up with Santa just as he realizes he's short one gift. Reward: the little elf gets a new office and a new title—``the boss.'' As he did in Elmer Blunt's Open House (1992), Novak tells the story mostly with his tidy, comical illustrations, in deftly designed, creatively varied comic-strip frames. Fans of Raymond Briggs's Father Christmas (1973) will be delighted to discover this new treat. (Picture book. 4-8)