There is so much packed into this episode and most of it is awful. There is the indiscriminate killing of ill-defined characters, a surprise pregnancy, a ten-minute transformation into a martial arts expert and a ridiculous conspiracy hidden in a secret room that’s bigger on the inside.
In its half century Doctor Who can explain away nonsense with the claim that the Doctor lies, or that alternate timelines exist, etc., but Class does not have that luxury. Coal Hill has had at least two Doctors and five companions, yet none of them have ever noticed any suspicious activities by the Board of Governors? The “refurbishment” from school to academy doesn’t work as enough of an excuse.
Whoever the B.O.G might be, they come from nowhere and “manage time” and wait for the “arrival” and set up a cliffhanger that will likely never be resolved. Word is that the creator/showrunner has quit, so season two has become even more unlikely.