Susan

Susan is the Doctor's granddaughter.  When he made his decision to leave Gallifrey, he was reluctant to leave her behind, and so took her with him.   The Doctor's original aim was simply to run, without a destination in mind, and he "borrowed" a battered Type 40 machine.  Unfamiliar with the controls, he was forced to utilize a notebook in which he had copied down the operational codes in order to have any control over the old ship.  Susan had in fact been the person who had invented the acronym TARDIS used to describe the TT Capsules--Time And Relative Dimension In Space.

Some of the travels the Doctor and Susan undertook together are unrecorded.  There is mention of a stay on the planet Quinnis, and she had obviously visited France at the time of the French Revolution (the Doctor apparently enjoyed the attempts to overthrow a corrupt ruling body and install a rational system), but little is known of their other adventures together.  However, Susan clearly did not like their restless meanderings throughout time and space as much as the Doctor.  When the TARDIS suffered a massive systems failure and crashed landed on Earth in 1963, she was more than glad to settle down to lead a "normal" life there.

The TARDIS had arrived in a deserted junkyard in Totter's Lane, London, originally owned by a mysterious I.M. Foreman.  Adopting the surname, Susan was able to enter the local Coal Hill School.  She soon found the pace of life there to her liking, though she did not make friends.  Unable to invite anyone home with her--how could she explain that the police box was her home?--she tended to be lonely and aloof.  But she found the primitive simplicity of the time to be fascinating.   She loved the London fogs, and the perverse safety that night cast over the city.

Unhappily, her alien nature led to trouble.  She was terribly ignorant of the conditions of the day, since most of her information about the Earth had been picked up on her various travels and was not always either accurate or organized.   She muddled her time-periods, and exactly what was known of science and history.   In the end, her strange manners and knowledge raised suspicions in the minds of her two teachers, Barbara Wright and Ian Chesterton.  They followed her home one evening, and stumbled into the freshly-repaired TARDIS.

Susan's dreams of settling--at least for a while--in the twentieth century were dashed.  The Doctor, afraid of exposure  and perhaps even discovery by the Time Lords, set the TARDIS in flight again, carrying off the two teachers as well as himself and Susan.  When the TARDIS landed them in the Stone AGE, a run in with the primitive inhabitants resulted in the loss of the Doctor's notebook.  Thereafter, he was completely unable to program the ship, and its meanderings were even more random than before.

Susan, however, finally had friends.  Barbara and Ian--initially furious with the Doctor--finally settled into a truce.  Susan interceded on their behalf with her grandfather.  After an incident in which the TARDIS was almost destroyed, the Doctor finally made peace with the two teachers.   The Doctor's initial suspicion and dislike of the two teachers mellowed, and he began to see that even so-called "primitives" from Earth were people in their own right.  His own prejudices were confronted, and he began to acquire the more mature outlook that soon began to characterize him.  Susan, too, found the companionship of the two teachers to be rewarding.  For the first time in her short life, she had friends that she could confide in and who supported her.

She still lacked real contact with anyone of her own age, until the TARDIS took them to the year AD 1289, nd she met the Chinese girl, Ping-Cho.  The young woman was on her way to be married, and she and Suan struck up a friendship.   More and more as their enforced journey with the Venetian traveler Marco Polo progressed, Susan began to feel what it was like to settle down and to enjoy the company of people her own age.  She and Ping-cho were forced to say their goodbyes as the TARDIS took the Doctor and friends onwards, but Susan never forgot the young girl.

By the time of their arrival on the Sense-Sphere, Susan's outlook had broadened considerably.  To the Doctor's frustration and annoyance, Susan began for the first time to question his judgment and opinions.  In the past, she had always deferred to him, but now things were changing, and this disturbed the Doctor greatly.  As the two teachers realized, Susan was growing up.  She was looking for her own identity.

Force to deal with this, the Doctor too a deep, hard look at his granddaughter and her aims and desires.  She clearly did not enjoy the wandering life that he did, and she also longed for companionship and stability in her life.  Reluctantly, the Doctor was forced to make the very hard decision--to leave Susan behind at the first real chance.

It was very wrenching for him, but he had to be selfless about the decision.  Susan was clearly unhappy in their travels.  If she stayed behind, then there was very little chance that the Time Lords would ever find her.  Their tracking efforts would be centered on locating the TARDIS, and no matter how observant they might be, there was virtually no chance that they would ever find Susan if she were separated from the TARDIS.

The Doctor's moment of crisis came in the year AD 2167.  The Daleks had conquered and devastated the Earth, and the Doctor and his friends became involved with the rebels fighting to destroy the Daleks and to reclaim their world.   Susan became enmeshed with the fighters, and especially with young David Campbell, one of their leaders.  Soon she had clearly fallen in love with him, and he with her.

With the defeat of the Daleks, Susan was prepared to travel on, thinking that her grandfather needed her help to get along.  The Doctor, however, made the decision he had been dreading--he locked her out of the TARDIS, and forced her to remain behind with David.  Hard as it was for him, he knew that the challenge of rebuilding a civilization would be more in Susan's best interest than in further accompanying him on his meandering journey.

Susan settled down to marry David, and to be a farmer's wife in the new order.  Along with the other members of the old rebel groups, she was a founder of the reborn human race on the Earth.  She had found a home, a purpose, and a family that she had never known before, nor would even have been able to know on Gallifrey.

Her path intersected that of the Doctor only once after this.  Twenty years after being left on the ruined Earth, she was to take part in the machinations of Borusa, and her short reunion with her grandfather at this time remains the last known reference to her adventures.