A fearless band of adventurers comprising Wu Xie (Bai Shu), Zhang Qi Ling (Zhao Dong Ze), and Wang Pang Zi (Zhang Bo Yu) has been reunited aboard a train en route to the Chinese border with North Korea. Deep in the mountains, in a frozen, rugged wasteland off-limits for many years, is a huge fearsome underground palace that is shrouded in secrecy - but is also thought to contain untold treasures. For Wu Xie, the quest to unveil the mysteries of the palace is personal and family-related. But divisions have formed within the group, and they soon find themselves at loggerheads with one another, despite their once-strong bond as the "iron triangle." When they arrive at the palace, they soon discover that the building is a maze of booby traps and other pitfalls. It has also become home to fearsome giant insects and brutally strong birds of prey that show a deep dislike for visitors invading their territory. To complicate matters further, a former ally named Ning (Zhao Rui Han) has also set her eyes on finding the prize before Wu Xie and his team - and has led a gang of international mercenaries to the palace, intent on stopping Wu Xie at all costs.
