A mysterious letter sent to Wu Xie's late grandfather, Wu Laogou, disrupted the retirement plans of Wu Xie, Zhang Qiling, and Wang Pangzi. The letter points to a 'comet' tomb in Outer Mongolia, and the Iron Triangle decides to investigate, butUnexpectedly involved in an unimaginable adventure. The sinister Mongolian bandits, the countdown to the escape from the Comet's tomb, the eerie rules of the tomb chamber, and the invisible 'it'... The Iron Triangle had to be releasedHand to hand