I was reading a book where the main character has just enough money for a bus fare. He and the other passenger are transported to another dimension(?) or the future(?)
The protagonist seems to have been a warrior in a past life.
Possibly an Iris Wildthyme novel? There are a lot of them, and I'm not sure I've read any of them, so I couldn't be sure which one this is if any. Apparently she's not always from the same place or even the same literary universe in all her appearances, but in some of them she's a renegade Time Lady and drives a time travelling London bus.