In the second episode, the C21 Special Task Force takes on a major case when a daring daytime burglary occurs at three apartments in the E2 residential block. While the adults and local police handle the official procedures, the resourceful group of young friends—Minh, Son, Sang, Quang, and Tung—decides to launch their own secret investigation. By bravely inspecting the roof hatch at the crime scene, they discover crucial physical evidence left behind by the culprits, including Vinataba cigarette butts, a leather camera strap, cut nylon strings, and a large black button from a NATO jacket