Mentzer's other work included: IM-1 "The Immortal Storm" (1986), I-11 "Needle" (1987), and an adventure module for TSR's "Star Frontiers" game based on Arthur C. Clarke's novel "". Because of his work with the Gen Con game auction, Mentzer had become interested in the game memorabilia market, and along with James Ward and Jean Black, wrote "The Game Buyers' Price Guide 1986", which summarized current market prices for hobby games. Further annual editions were planned, but when Mentzer left TSR, the project was shelved.