Vicki travelled with the Doctor between The Rescue and The Mythmakers.

After leaving his Granddaughter on Earth, the Doctor, Ian and Barbara arrived on the planet Dido, in the 25th century. They discovered a crashed Earth space craft, with two survivors on board: a man named Bennett and a young girl, Vicki.

The Doctor discovered that Bennett had killed the other survivors, to cover up an earlier murder. When Bennett himself was killed, The Doctor invited her to join him in the TARDIS.

Vicki's relationship with The Doctor was very much as a surrogate granddaughter. He occasionally called her Susan by mistake and it was clear that there was that kind of relationship between them. She got on well with Ian and Barbara, too, and later with Steven, who at first seemed a romantic partner for her.

In an adventure in ancient Troy, Vicki fell in love with Troilus and decided to leave the TARDIS. She adopted a new name: Cressida.

Maureen O'Brien was born on 29 June 1943 in Liverpool. Her first TV role was in Doctor Who, and she appeared as Vicki in 38 episodes from January 2 to November 6, 1965, but since then has had little to do with the series. However, in 2006 she played the role of Miss Alice Bultitude in the Big Finish Productions Doctor Who audio play Year of the Pig, alongside Colin Baker and Nicola Bryant as the Sixth Doctor and Peri Brown.

She played unit general manager Elizabeth Straker in the second season of Casualty (1987). She has made guest appearances in Taggart ("Forbidden Fruit"), Cracker ("The Big Crunch"), A Touch of Frost ("Private Lives") and Heartbeat.

Maureen O'Brien has also written a number of detective novels Close-Up on Death (1989), Deadly Reflection (1993), Mask of Betrayal (1998), Dead Innocent (1999), Revenge (2001) and Unauthorised Departure (2003); all featuring the character of Detective Inspector John Bright.

Maureen O'Brien has also been a stage director. She directed Brecht's Caucasian Chalk Circle at Ottawa University, Canada, in the 70s and in the 80s she taught acting workshops in the USA and shows on the London Fringe. Her production of Mike English's Getting In in 1986 was Time Out's Critic's Choice.

As a playwright, her play The Cutting (Bush Theatre) was nominated Best Play (London Fringe Awards) and Best Newcomer (Evening Standard Drama Awards).

Film and TV

"Doctor Who" (38 episodes)
The Powerful Enemy (2 January 1965) - Vicki
Desperate Measures (9 January 1965) - Vicki
The Slave Traders (16 January 1965) - Vicki
All Roads Lead to Rome (23 January 1965) - Vicki
Conspiracy (30 January 1965) - Vicki
Inferno (6 February 1965) - Vicki
The Web Planet (13 February 1965) - Vicki
The Zarbi (20 February 1965) - Vicki
Escape to Danger (27 February 1965) - Vicki
Crater of Needles (6 March 1965) - Vicki
Invasion (13 March 1965) - Vicki
The Centre (20 March 1965) - Vicki
The Lion (27 March 1965) - Vicki
The Knight of Jaffa (3 April 1965) - Vicki
The Wheel of Fortune (10 April 1965) - Vicki
The Warlords (17 April 1965) - Vicki
The Space Museum (24 April 1965) - Vicki
The Dimensions of Time (1 May 1965) - Vicki
The Search (8 May 1965) - Vicki
The Final Phase (15 May 1965) - Vicki
The Executioners (22 May 1965) - Vicki
The Death of Time (29 May 1965) - Vicki
Flight Through Eternity (5 June 1965) - Vicki
Journey Into Terror (12 June 1965) - Vicki
The Death of Doctor Who (19 June 1965) - Vicki
The Planet of Decision (26 June 1965) - Vicki
The Watcher (3 July 1965) - Vicki
The Meddling Monk (10 July 1965) - Vicki
A Battle of Wits (17 July 1965) - Vicki
Checkmate (24 July 1965) - Vicki
Four Hundred Dawns (11 September 1965) - Vicki
Trap of Steel (18 September 1965) - Vicki
Airlock (25 September 1965) - Vicki
The Exploding Planet (2 October 1965) - Vicki
Temple of Secrets (16 October 1965) - Vicki
Small Prophet, Quick Return (23 October 1965) - Vicki
Death of a Spy (30 October 1965) - Vicki
Horse of Destruction (6 November 1965) - Vicki

`
"Doctors" .... Doreen Crossland (1 episode, 2003)
- Good Grief (2003) TV Episode .... Doreen Crossland
"Heartbeat" .... Joyce Greaves / ... (2 episodes, 2000-2003)
- The High Life (2003) TV Episode .... Joyce Greaves
- Wise Guys (2000) TV Episode .... Mrs. Emily Poole
The Blind Date (2000) .... Mrs. Smythe
The Closer You Get (2000) .... Dollie
"A Touch of Frost" .... Marion Williams (1 episode, 1999)
- Private Lives (1999) TV Episode .... Marion Williams
Falling for a Dancer (1998) (TV) .... Corinne Sullivan
The Land Girls (1998) .... Mrs. John Lawrence
... aka Trois Anglaises en campagne (France)
"The Bill" .... Joy Grainger / ... (3 episodes, 1993-1997)
- Sparks (1997) TV Episode .... Margaret Ames
- Other Voices (1995) TV Episode .... Joy Grainger
- Coming to Terms (1993) TV Episode .... Pat Tolman
"Jonathan Creek" .... Kirsten Holiday (1 episode, 1997)
- Jack in the Box (1997) TV Episode .... Kirsten Holiday
The Fortunes and Misfortunes of Moll Flanders (1996) (TV) .... Mrs. Richardson
... aka Moll Flanders (UK: short title)
The Sculptress (1996) (TV) .... Sister Bridget
A Royal Scandal (1996) (TV) .... Lady of Edinburgh
"Cracker" .... Virginia Trant (1 episode, 1994)
- The Big Crunch (1994) TV Episode .... Virginia Trant
"Taggart" .... Ruth Millar (1 episode, 1994)
- Forbidden Fruit (1994) TV Episode .... Ruth Millar
"Casualty" .... Elizabeth Straker (15 episodes, 1987)
- These Things Happen (1987) TV Episode .... Elizabeth Straker
- Burning Cases (1987) TV Episode .... Elizabeth Straker
- Peace, Brother (1987) TV Episode .... Elizabeth Straker
- Fun Night (1987) TV Episode .... Elizabeth Straker
- Hooked (1987) TV Episode .... Elizabeth Straker
(10 more)
Zina (1985) .... Natalya
She'll Be Wearing Pink Pyjamas (1984) .... Joan
On the Shelf (1984) (TV) .... Linda
"Play for Today" .... 1st Social worker / ... (2 episodes, 1980-1982)
- John David (1982) TV Episode .... 1st Social worker
- C2 H5 OH (1980) TV Episode .... Jill Secombe
"Bergerac" .... Joan Hadley (1 episode, 1981)
- Relative Values (1981) TV Episode .... Joan Hadley
"Tales of the Unexpected" .... Janet (1 episode, 1980)
... aka Roald Dahl's Tales of the Unexpected
- Depart in Peace (1980) TV Episode .... Janet
The Legend of King Arthur (1979) (TV)
"Oresteia" (1979) (mini) TV Series .... Electra
"The Poisoning of Charles Bravo" (1979) TV Series .... Florence Ricardo
"The Lost Boys" (1978) (mini) TV Series .... Mary Barrie
"The Devil's Crown" .... Mathilda (1 episode, 1978)
- Tainted King (1978) TV Episode .... Mathilda
"The Duchess of Duke Street" .... Lizzie (1 episode, 1976)
- Trouble and Strife (1976) TV Episode .... Lizzie
"Victorian Scandals" .... Skittles (1 episode, 1976)
- Skittles (1976) TV Episode .... Skittles
"The Whiteoaks of Jalna" (1972) TV Series .... Alayne
"Z Cars" .... Nora Leach (2 episodes, 1969)
- Not That Sort of Policeman: Part 2 (1969) TV Episode .... Nora Leach
- Not That Sort of Policeman: Part 1 (1969) TV Episode .... Nora Leach
Light Blue (1968) (TV) .... Jane Peel
"The Wednesday Play" (1 episode, 1968)
- Light Blue (1968) TV Episode
Mr. Dickens of London (1967) (TV)
"Thirty-Minute Theatre" (1 episode, 1967)
- Taste (1967) TV Episode