It's not for no reason that this is one of the most highly regarded of the Discworld series.
It's essentially a pretty basic story of cops and robbers, with Vimes in his copper role, chasing the awful criminal Carcer. Of course, this is Ankh-Morpork, so the fact that this chase is quickly complicated by a magical disturbance in time (is it the same disturbance that comes from the events in 'A Thief of Time'?) that sends both back to a formative period in the city's history, should probably be no surprise.
It is the ending of the rule of the Patrician Lord Winder and there is a revolution in the air. Vimes takes the place of his own mentor from decades past, as he leads the nascent watch to defend the citizens of the city against the oppression of the governemt and the 'Unmentionables', a shady secret police acting on behalf of the Patrician, and who Carcer adopts as his own side. We see a young Vetinari as a bookish student of the Assassins guild, making his mark on the city by ending the Patrician Winder, to make way for his own predecessor. A young Vimes, who is taught the way of the copper by old Vimes' best impression of his mentor Keel. Nobby is a lovable street urchin and Colon is there too.
I've read this book quite a few times now, but never having read all the other earlier books before now, and it offered some new perspective that made me enjoy it all the more.
Finished reading - 22/03/26