It’s always tough to be the first replacement in a winning team. The staggering success of Doctor Who’s first series, way back in 1964, created a certain mythology around the key four characters, the Doctor, Susan, Ian, and Barbara. And when you consider this was a time before the idea of interchangeable companions (and interchangeable Doctors) the arrival of a new face among the team was a big deal.
In fact, when Carole Ann Ford elected to leave the TARDIS in 1964, the production team of the time sought to find a replacement for the young, headstrong Susan, to keep the chemistry going. Enter Vicki (a girl whose surname was never made clear), a teenage orphan from the 25th Century, who ably filled the gap left in the Doctor’s life by the departure of his granddaughter.
Of course, Susan was more used to the ways of the traveling Timelord than Vicki – played by Maureen O’Brian – and so for the first few adventures, she took a passive role, hiding behind Ian and Barbara and generally bringing the screams. But the Doctor soon took her under his wing