Sir Ian of Chesterfield, that's his name. Too bad the faculty at the Cold Hill School would never believe he had been knighted by King Richard the Lion Hearted himself. And to think that just a couple episodes before that Sir Ian had been a galley slave. What happens is the TARDIS materializes in 12th century Palestine, during the time of the Third Crusade. They quickly become enmeshed with the Crusaders, led by King Richard, and their fight against Saladin. Barbara ends up being held by Saladin while the others are in the court of King Richard. Ian, in desperation to rescue Barbara, petitions King Richard to aid in the rescue, and in the end Ian is knighted so he would have appropriate rank to bargain with Saladin, and sent on his way to attempt the rescue. Barbara, in the meantime, escapes and is recaptured a couple times. There's a little subplot with Haroun whose family was destroyed by Saladin. Barabara encounters Haroun's daughter in Saladin's harem. Eventually Ian and Haroun enter the Harem and free both Barbara and Haroun's daughter. They make their way back to the Doctor and Vicki, get in the TARDIS and leave.
