Drona Parva covers the war's middle stretch under the command of Drona, the Pandavas' and Kauravas' shared martial teacher, now leading the very students he once trained in battle against half of them. Its most devastating episode is the death of Abhimanyu, Arjuna's teenage son, who alone among the Pandava forces knows how to penetrate the Chakravyuha, a complex spiral battle formation, but had only overheard the technique for entering it while still in his mother's womb and never learned how to fight his way back out; trapped inside and surrounded, he is killed by multiple senior Kaurava warriors converging on him at once in a manner the epic itself frames as a grave violation of accepted rules of combat. Arjuna's grief and fury at learning of his son's death, and at the dishonorable manner of it, drives the war's emotional pitch to a new intensity, and he vows to kill Jayadratha, the king who had blocked reinforcements from reaching Abhimanyu, before the next sunset or die himself.
Drona's own death follows soon after, engineered when Yudhishthira, under pressure from Krishna's strategy, announces the death of "Ashvatthama," technically true of an elephant given that name but deliberately misleading, causing the grief-stricken Drona to lower his weapons long enough for Dhrishtadyumna to behead him.