Gao Yang redirected all his attention back to the target area he had just abandoned, focusing entirely on the window behind which a bright light had just flashed. Above the shipyard that had been illuminated, there was an awning that made the room even darker and more difficult to observe. But it was precisely because of the awning above the window that Gao Yang was able to spot an inconspicuous streak of light on the windowsill.
Under the blazing sun, looking from outside into a window, one would find darkness within; it was very hard to see anyone hiding inside with the naked eye. Although Gao Yang detected the light, he quickly realized that the particular window was actually not receiving any direct sunlight, so the source of the flash remained a mystery.