Hermione happened to overhear Professor McGonagall and Professor Flitwick talking outside the Charms classroom. The gist of it was that they could no longer speak freely in the staffroom, because Umbridge was always there.
And that was not even the most outrageous part. The most outrageous part was that, the day after the Azkaban Breakout, a new decree from the Hogwarts High Inquisitor appeared on the noticeboard.
Teachers were forbidden to provide students with any information unrelated to the subjects they taught.
Soon, however, this was amended to forbid providing any information unrelated to subjects covered by the syllabus, without restricting teachers to their own subjects.
The reason was simple.
On the very day the original rule was issued, all the sixth- and seventh-year students taking Ancient Runes lodged a joint protest.
Under the rule, Professor McGonagall and Professor Flitwick would no longer be able to explain runes to them. That was something they simply could not accept.
Professor Babbling was always elusive, while Ancient Runes was notoriously obscure and difficult.
Normally, Umbridge should not have cared in the slightest about students' grades in any particular subject. But among the students protesting were three rather troublesome individuals.
Irina Alex, a sixth-year Slytherin prefect; Rowles Prewett, a seventh-year Slytherin prefect; and Carrie Rowle, a seventh-year Ravenclaw prefect.
All three prefects had chosen Ancient Runes and stuck with it until now. They simply could not tackle those obscure runes on their own without consulting their professors.
Normally, Umbridge paid no attention to students' opinions, but these three students were somewhat special.
First, all three children came from pure-blood families, members of the so-called Sacred Twenty-Eight.
Second, these three children's parents and elders all held considerable influence in the Wizarding World of United Kingdom. Some even held fairly senior positions in the Ministry