"I found it a little bit stressful, because I wasn't used to working with Doctor Who. I got the impression I'd walked into the end of seven years and it was all a bit tense"

Sarah Sutton's quote is likely describing her experience of joining the cast of Doctor Who in the fourth season. She was most likely overwhelmed by the fact that she was joining a show that had currently been running for 7 years and was currently established. She was likely unfamiliar with the show and the characters, and felt the pressure of needing to quickly discover and adjust to the program's dynamics. She was most likely likewise daunted by the truth that she was joining a program that had already been running for seven years and had a big fan base. She was most likely feeling the pressure of having to measure up to the expectations of the show's fans and the program's developers. Overall, Sarah Sutton's quote reflects the tension and pressure she felt when joining the cast of Doctor Who in the 4th season.