After the escape from the house of lac the brothers cross into forest country and Bhima kills the rakshasa Hidimba, whose sister Hidimbi has already fallen in love with him. Kunti allows the marriage on terms, and the terms are Hidimbi's undoing as a wife: Bhima will stay only until a son is born, and then return to his brothers. The son, Ghatotkacha, is born and reaches his full growth at once, which is what the epic says of rakshasa children, and he leaves with his mother.
He returns in the war and his death is the point of him. Karna carries the Vasavi Shakti, a single use weapon given by Indra in exchange for the armour Karna was born with, and he has kept it for Arjuna. Ghatotkacha fights by night and does such damage that Karna spends the weapon on him to save the army. Krishna, told of the death of a nephew, is described as delighted, because the one shot certain to kill Arjuna has now been used on someone else. Ghatotkacha's life exists in the plot to be spent.
Hidimbi has an afterlife the epic does not give her. She is worshipped as Hadimba Devi at Manali in Himachal Pradesh, in a wooden temple that stands over a rock shrine and draws pilgrims and visitors alike, where the forest woman married on a condition is the presiding goddess of the valley rather than an episode in someone else's exile.