A long, long time ago a man from a planet named Gallifrey was born. His people are known as Time Lords.
One day, he decided he needed to get away so he stole a T.A.R.D.I.S or Time and Relative Dimension in Space. This time machine allows him to travel in space and in time. Not only can is it capable of that but it is also bigger on the inside. What does that mean? While on the outside it only looks like a small police call box on the inside it is huge with hundreds of rooms, including three pools and a library.
He took it upon himself to save as many people and perform as many heroic acts as he could after his planet was destroyed during the Time War. The Time War destroyed his planet and left him as the lone survivor and last of the Time Lords.
This man goes by the name of the Doctor. He is over two thousand years old. How can he live to be that old you ask? Gallifreyans have a way to sort of cheat death, by way of regenerations. In fact he has gone through twelve different regenerations at this point. When the Doctor regenerates, everything about his outward appearance changes - his face, hair, body, everything. His personality also changes but to his core he remains true by only wanting to help.
The Doctor also travels with companions. These people help guide the Doctor with decisions when he is struggling to make the right choice because, like us, he is still controlled by emotion. He is an eccentric, yet compassionate alien. In the past he's had adventures that took him anywhere from WWII to the Roman Empire, and the last day of Earth's existence.
The Doctor travels to India because he hears about Vishnu, and he believes Rama (who is an incarnation of Vishnu) to be a Time Lord! Throughout this storybook, the Doctor will have multiple run-ins with Rama and Sita and get into a lot of trouble. Each week he will experience a new adventure, because with the Doctor it's next stop, EVERYWHERE.
The eleventh Doctor inside his TARDIS