Ye Han, chief instructor of the “Dragon Abyss” special forces unit, is forced to retire after his identity is exposed during a covert operation overseas. After lying low for three years, he returns to the city as a food delivery rider. From dealing with a drunken bully to taking on an underground casino single-handedly, and from exposing financial scams to building a security conglomerate, this modern-day military ace moves between a delivery box and a bulletproof vest. Using a Beidou positioning System to track drug lords and military-grade drones to monitor corporate battles, he is writing an urban legend the hard way.