Anthony Stewart Head plays Rupert Giles, the school librarian and watcher. His job? To watch over the Slayer, teach her what she needs to know, provide a balance of discipline and friendship with the Slayer. Giles, does what he can to prepare the slayer for her duties but sometimes that isn't good enough.

He had a rocky relationship with Ms. Calendar which came to many stops over time. First, when he was discovered to have a hidden past that put Jenny in a life or death situation, he was forced to have to live with her rejection. Then, when she was discovered to be a gypsy who could have stopped Buffy and Angel from making the mistake that made him evil. Buffy and Giles shunned her after they found out but in Passion, Buffy told her she didn't want Giles to be alone. However, Angel killed her in that episode and left a huge scar for both Giles and Buffy.