In the heart of an unknown city, a mysterious figure, codenamed 'Chis', prowls the streets. With no discernible motive or target, Chis' nightly excursions are a puzzle, leaving the authorities baffled. The only clue is a cryptic symbol spray-painted at each scene, a chiseled 'X' with lines extending like rays of the sun. As the nights grow darker, so too does the mystery, and the city waits with bated breath for the next enigmatic appearance of Chis.