Sean Harris, better known as Bernie Harris, was a nineteen year old petty thief from Splott.
Bernie was born in July 1988. He got his nickname Bernie at the age of twelve when he burned down his neighbour's shed with cigarettes. Bernie was unpopular in his neighbourhood. He got thrown out of his house and bought a flat on Evelyn Street. Even his own mum wouldn't allow him home until he gave her the fifty pounds he owed her. When questioned by Torchwood, a boy complained about being cheated out of an iPod and stolen cigarettes, a man called him "bad" and a woman contemptuously said she "wouldn't piss on him if he was on fire".
At some point Bernie stole a quantum transducer from a storage unit that had belonged to what he called a crazy old man. He thought about selling it at Antiques Roadshow. With it he saw a woman putting her dead baby in a waterway. He visited her and she gave him money not to tell anyone. Using it again, he saw the murder of Lizzie Lewis and tried to blackmail Ed Morgan, her killer. Morgan refused to give him anything.
When Bernie used the other part of the transducer, it allowed him to see the future. Unfortunately, his experience was grim and highly traumatic- he saw himself dead on the road outside his house, still young and covered in blood, strongly implying that he was going to be murdered. He decided never to use that half again.
In 2007, Torchwood Three detected the transducer and sent Gwen Cooper, Owen Harper and Jack Harkness to capture Bernie. Gwen snatched his hoodie, but Bernie escaped in Cardiff Central Station. While passing through Splott at a later date, Owen saw Bernie and pursued him. After a long chase through the gardens of several residents, Owen caught him.
They went to a pub and Bernie told Owen and the rest of the Torchwood team how he had come to own the piece. To stop them leaving, he told them he had the second half. They went to Bernie's flat and he gave it to them. They also took a tin containing alien money and rocks he had stolen from the same man.
Bernie told Gwen about having seen his death and she told Jack. To boost his confidence, Gwen visited him again and told him it was only one of many possible futures. Bernie went outside after this to confront Morgan, who was threatening to kill him. Scared, Bernie told him he would keep his secret and the Torchwood team disarmed Morgan, saving Bernie's life. (TV: Ghost Machine)