I'm at a point in my novel where the next couple of chapters (at least) will cover a kind of running battle through a city while the main characters are being chased by a nasty creature. The three main characters are all mages, so this chase sequence will serve as a way to showcase all of their individual talents and let them totally go crazy in a variety of progressively more absurd settings like a brothel, a butcher shop, and a few other places yet to be decided, and this will be the culmination of the second big story arc within the novel, setting up the final act. My question is this: How long can such a chase sequence really last? I want this to be a long, drawn out affair but I also don't want the reader to get bored with it and start skimming over it to get to the next part. Thinking about some action movies like Die Hard and others where the whole movie is just a long series of action sequences, it seems to me like the trick to it is switching gears from time to time and letting the reader's excitement kind of die down a bit, or inserting something hilarious to give it a different flavor before returning to the action. Anyone have any suggestions?