The Doctor attempts to return the scientists to their own time, before Linx tries to use his spaceship and destroys the entire castle.
Did You Know?
Originally, it was the Doctor and not Hal who killed Linx by shooting an arrow into the Sontaran's probic vent. See more
Sarah appears to have an unexplained costume change from attire appropriate for the time back to her modern clothes. In DVD commentary, it is suggested she changed in the TARDIS and not showing it was an error, though only the Doctor is shown visiting the TARDIS. However, she got her native clothing from Sir Edward's castle and she had returned there, giving her opportunity to change back into her 20th century attire and return the other clothes. As she is returning to Irongron's castle to defeat Linx, it would be natural to think she would also be expecting to return to her own time soon with the Doctor and want her original clothes again. See more
You are truly a great magician, Doctor.
To tell you the truth, Hal, I'm not a magician at all.
Sarah Jane Smith
I'm not so sure about that.
[the Doctor enters the TARDIS, followed by Sarah, and the door closes. Hal is momentarily startled as the TARDIS's engines start up and the blue box magically disappears before his eyes