As the Discworld hurtles towards the great red star and its magical field burns away much like our own ozone layer, frightened and bewildered people start to listen to demagogues like Dahoney. The new cult believes that the great red star has been sent to purge wickedness and that in these, the Last Days, it will cleanse and scour and purify the Disc. So come, friends, let us paint the holy sign of the Red Star on our foreheads, and go forth, and intently stare at the left ears of those we are about to cleanse and scour and purify whilst telling them this is for their own good. Let us burn the things of magic and destroy the shrines of the Gods who have manifestly failed to protect us and who, therefore, do not exist and we no longer need. And let us in passing deal with lesser races such as Dwarfs—they can die along with the wizards! And all those who do not have the sign of the Star upon their brows!
The Star directs that the Disc must be purified!
All of which insanity happens during the events of The Light Fantastic.
At the end of The Light Fantastic a large mob of Star People and other citizens of Ankh-Morpork laid siege to the Unseen University and attempted to break down its gates. With magic failing across the Disc, it was not the best time for the wizards to consider if they should have included a non-magical way of locking the gates, such as a big bar.
The angry mob demanded that the wizards either: (A) stop messing about and get rid of the red star, or, and this option was favoured by the Star People, (B) kill themselves.
The wizards had no idea how to do A, no intention of doing B, and most had in fact opted for C, which was to escape out the back door and leg it at high speed. This left only the Council of Wizards and Archchancellor Trymon and his plan to read the Octavo anyway without the eight spell.
"Star People" is also the translation of "Eldar", name of a division of the Elven race in J.R.R. Tolkien's notion of the Sundering of the Elves.