The case of a Gloucester woman who vanished 21 years ago is being reopened by police, who will try to build up a picture of her final days.
Librarian Angela Bradley, who was 34 at the time, was last seen in Gloucester at about 19:00 GMT on 16 January 1995.
Her car was later found, with the keys in the ignition, near Mythe Bridge, in Tewkesbury.
Mrs Bradley's brother, Philip Miles, said she was a "very intelligent" woman whose disappearance remained a mystery.
He has provided a DNA sample so it can be checked against details of unidentified bodies held by the Missing Persons Bureau.
He said his parents had died without knowing what had happened to her. The family remained "in limbo" and he still wondered what had happened to her - especially on birthdays and at Christmas: "I would very much like to see Angela again, if that's possible."
He said his sister had suffered from anorexia and had attended Coney Hill mental hospital until it had closed in 1994, after which she was placed in a house in Gloucester. It was while she was staying with her parents for the weekend that she disappeared.
Mr Miles said: "We had a lot of conversations about what might've happened - it's a total mystery."
Gloucestershire Police want to build up a picture of what happened in the days before she vanished and are hoping more people who knew her will get in touch.
Insp Andy Matheson said detectives from the National Crime Agency were helping with the case.
He said: "We don't know if Angela has been murdered, we don't know if Angela took her own life - we don't know if she has decided to disappear and reinvent herself and is still alive and well somewhere else - which is obviously the outcome we are hoping for."