Rama and Sita were out in the forest when Ravana the demon disguised himself as a wounded deer to attract the attention of Sita. Sita asked Rama to search for the deer and he did. Before he left to go find the deer, he put Sita in a magical circle to protect her.
When Rama went looking for the deer, the evil Ravana disguised himself as an old beggar who wanted a drink. He tricked Sita into leaving the circle and kidnapped her in his flying chariot.
When Rama returned he realised that he had been tricked and went to find Sita. On his way in the forest he found the monkey king Hanuman. Hanuman agreed to help Rama.
Hanuman and Rama gathered a monkey army and set off to find Sita. After searching for a while, they finally found Sita trapped in Ravana's prison on the Island of Lanka.
The battle lasted 10 days and Rama never thought he'd win. He then realised that he had a golden arrow given to him by the gods. Taking his golden arrow, Rama aimed at Ravana and won back Sita.
On returning home that night the people in the village placed lamps in their windows to guide them back home. There were more lamps than stars that night. Every Diwali, people light candles and celebrate this story that light triumphs over darkness and good triumphs over evil.