Doctor Who
There are several teachers believed to be Doctor Who at BRGS. This should be impossible, but as Timelords regenerate and can travel in time it's obvious that he regenerated into these three at some point.
Doc Rob must be doctor who simply because of the amount of work he does, he could neber get it all done in time, so he must have a tardis. The fact that he ha been here forever can be explained by timelord's ability to regenerate, and he never leaves the school because the doctor never goes far from his tardis.
Mr. Neve is believed by some of year 10 to be Doctor Whjo because he can actually nuderstand Shakespearean English, therefore he must have met Shakespear and therefore must be Doctor Who. His tardis is either hidden in the cupboard in T5 or is actually the entirety of T rooms 3, 4, 5 and 6, explaining how they got there so quickly and they do actually look bigger on the inside.
Mr. Ventress must be Doctor Who simply because anyone who dresses like that cannot be from this time period.
It is believed that all three doctors are here to fight together against the most evil time lord ever, Lord Morris. Lord Morris may also be a Dalek.