In plain words
After the marriage, the king of Kekaya took Bharata to his own kingdom. Śatrughna too went along with him. When Rāma, bowing to His father's command, was going to the forest, Lakṣmaṇa too went along with Rāma, though his father had not told him to. As Lakṣmaṇa went about at Rāma's side and Śatrughna at Bharata's, it seemed to onlookers as if Rāma and Lakṣmaṇa were one pair and Bharata and Śatrughna another. But the brotherly Prema the four bore one another had no equal.
Mother Sītā too made ready to go to the forest with Rāma. Lakṣmaṇa too went with them, in order to serve them. As Sītā, Rāma and Lakṣmaṇa wandered in the forest, they came upon an āśrama. When they asked whose āśrama it was, they learned that it was Agastya's. Seeing Sītā, Rāma and Lakṣmaṇa, the great sage Agastya and the other dwellers of the āśrama rejoiced greatly and welcomed them. They thanked them for having sanctified their āśrama. Later, in the course of their talk, the great sage Agastya: “Rāma! If You stay in this āśrama, You will not live in comfort. Not far from here lies the Daṇḍaka forest. There You will be comfortable in every way. Mother Sītā too will have no hardship of any kind. There You will find as much fruit as You need to eat. The sacred river Godāvarī too flows right there. So make Your dwelling there,” he advised. Following his advice, Sītā, Rāma and Lakṣmaṇa built a hut of leaves on the bank at Pañcavaṭī in the Daṇḍaka forest and passed their days in comfort.
Many kinds of animals roamed about that āśrama. One day it happened that Sītā saw a golden deer. Sītā knew: why would Sītā, who had left all the gold ornaments she owned behind in Ayodhyā and come to the forest, have any craving for a golden deer! She knew that no golden deer can be born in this world. She thought it must be some deer of illusion. But fate is mighty. Though she knew a golden deer could not exist, she asked Rāma to catch it and bring it. “Rāma! How beautiful this deer is! If You catch it and bring it, we can keep it near our home, play with it and pass the time happily. While You roam the forest, I am left at home alone. Will You not give me this little joy?” she pleaded. “Very well; your joy is our joy,” said Rāma, and made ready to catch the golden deer and bring it back. Then Lakṣmaṇa: “Brother! This is a deer of illusion; it is no real golden deer. It seems to me that some demon has worked a trick and taken on this form. Even so, You need not go to catch it. I will go,” he said. But they say that when danger is on its way, the intellect does not work rightly. “Only You can catch it and bring it,” Sītā said, and pressed Rāma Himself to go. At that moment her intellect worked that way. Urged on by Sītā, Rāma went chasing that deer of illusion. After going some distance He let loose an arrow. As it struck, the demon took on his true form and gave up his life crying, ‘Hā Sītā! Hā Lakṣmaṇa!’ To Sītā it sounded like Rāma's voice. “Lakṣmaṇa! Go, go, go to Rāma's help at once. Rāma seems to be caught in some danger and calling us,” she said. Then Lakṣmaṇa: “Mother! This may be some demon's trick. No danger can come upon Rāma. Have courage,” he said. As Lakṣmaṇa would not move from there, Sītā heaped blame on him in many ways. “Are you hoping to have me for yourself if Rāma is gone?” she said, speaking harsh words. Unable to bear these words, Lakṣmaṇa set out from there at once.