During the late Eastern Han Dynasty, a massive peasant uprising erupted, and Kong Rong, the Chancellor of Beihai, found himself besieged in Ducheng by the rebel leader Guan Hai. The situation grew dire. Kong Rong urgently dispatched his warrior Taishi Ci to break through the encirclement and seek reinforcements from Liu Bei. Taishi Ci fought his way out and reached Liu Bei, pleading, "My lord Kong Rong is trapped and needs your aid." Liu Bei, impressed by Taishi Ci's bravery, replied, "I have long heard of Kong Rong's virtue—how could I refuse?" He then led troops to lift the siege, saving Kong Rong from certain doom.
Donglai native Taishi Ci's mother had once received assistance from Kong Rong. She said to Taishi Ci, "You have never met Kong Beihai, but when you were away, he often gave me help and gifts, surpassing the kindness of old friends. Now that he is in trouble, you should go and help him."
At this time, the siege was not yet tight. Taishi Ci slipped into Duchang City under cover of night. He met Kong Rong and requested, "Let me lead a force out of the city to strike the enemy hard." Kong Rong did not listen, wanting to wait for outside reinforcements. But days passed, no help arrived, and the siege grew increasingly urgent.
Kong Rong wanted to ask Liu Bei, the governor of Pingyuan, for urgent help, but no one in the city could get out. At that moment, Taishi Ci volunteered to go alone. Kong Rong worriedly said, "I'm afraid it won't work. The city is now besieged so tightly that everyone says we can't get out. Brave as you are, you can't make it either!"
Tai Shi Ci replied, "You once helped my mother; she felt grateful and sent me to solve your problem. I will find a way out." Kong Rong had no choice but to agree.
Taishi Ci prepared his gear, ate and drank his fill, and just as dawn broke, he led two riders charging out of the city gate. The besieging soldiers outside were startled, their ranks thrown into chaos. Taishi Ci rode to the moat beneath the city wall, drew his bow, and shot two soldiers dead, then galloped back inside. The next morning, he did the same—some of the besiegers scrambled up, others still lay about—and after firing two arrows, he returned. On the third morning, he repeated the act, but this time the encircling troops all stayed flat on the ground, none rising. Taishi Ci then whipped his horse into a furious sprint and broke through the siege. By the time the enemy forces realized what was happening, he had already escaped beyond their encirclement.
When Taishi Ci arrived at Pingyuan, he said to Liu Bei, "Guan Hai has rebelled, and Kong Beihai is besieged with no allies—his fall is imminent. Because you are known for your righteousness and willingness to help those in crisis, Kong Beihai thinks of you day and night, straining his neck in hope of your aid. I risked my life to break through enemy lines to beg for your help. Only you can save Kong Beihai now!"
Liu Bei replied gravely, "The renowned Kong Rong, Chancellor of Beihai, even knows of my existence—that is an honor!" He immediately dispatched three thousand elite troops to follow Taishi Ci to the rescue.
When the besieging army of Guan Hai learned that reinforcements were approaching, they quickly lifted the siege and fled.
Kong Rong was saved and said to Taishi Ci, "You are my dear young friend!" Afterward, Taishi Ci returned to his mother. She said happily, "My son has finally repaid Kong Beihai for me!" Later, the idiom "danger at dawn or dusk" came to describe imminent peril.
Source: *Records of the Three Kingdoms*, "Biography of Taishi Ci"
Meaning of the Idiom: Later, the Chinese idiom "危在旦夕" came to describe imminent peril.