Four modern-day roommates travel back to ancient times, starting out with nothing but a single barren mountain. What others see as a locust plague, they turn into grilled skewers; water dragon insects become garlic lobster. They hold new product launches for colored-glass mirrors, scented soap, and refined salt, then use a silent bidding strategy to keep the imperial court and Prince Pingxi firmly under their control. A fake political marriage becomes a real marriage. After three years of preparation, they annihilate 20,000 elite imperial soldiers at the mountain pass, capturing the Dongyuan Basin with zero casualties. From being banned from selling their goods and surrounded by enemies to forming a three-party alliance and dividing the realm, they turn every losing battle into an overwhelming victory.