Bourne discovers some secrets to his identity through his only clue - the account number to a bank vault in Switzerland. He realises he is a skilled fighter when he is attacked, and discovers passports linking him to various different people. These aliases hint that he worked for a secret agency, but he cannot be sure. A CIA group is on his trail, and the agents seem desperate to keep him away from the truth. He eventually learns that he trained as an assassin for the American secret service, and starts to uncover the secrets behind his true identity - such as his final target, a man called Wombosi.
In The Bourne Supremacy, Bourne and his girlfriend Marie are living in India. After being framed by a Russian agent, he is hunted down. In the resulting car chase, his jeep plummets into a river, and Marie dies. He hacks into a CIA phone call to the police unit which had briefly arrested him, and learns about the CIA's involvement. He then continues to trace events from his past, in order to clear his name from the growing conspiracy.
The Bourne Ultimatum starts when Bourne discovers that a Guardian newspaper correspondent called Simon Ross has learned about Operation Treadstone, and so he tracks him down. When they meet, Bourne fails to get the journalist to safety - Ross gets scared and makes a run for it, only to be shot by a CIA assassin. Bourne discovers that the informant who spoke to Ross was Neal Daniels, but only finds him with the help of Nicky Parsons, a former Treadstone worker. They track him to Tangiers, but once more Bourne fails to reach him in time. Finally Bourne heads to New York, in an desperate attempt to recover documents about his previous life from the CIA.