Halfway through the evening self-study, without any warning, the lights in the classroom flashed a few times, and then went out with a "pop". Darkness swallowed everything in an instant, and there was a chaos of screams and the sound of tables and chairs clashing. Chen Sijin suddenly raised his head from the exercises, his heart beating uncontrollably. Before he could calm down, a cold mechanical voice came from the radio: "..." Chen Sijin's hand unconsciously clenched the pen tightly, and an ominous premonition filled his heart.
