Thanks for taking the time and trouble to read and review.
I do actually explain what they are about. Moving from one version to another moves you to another era (it's not time travel as they're not connected to each other).
A very rich neo-pagan from May and Max's time wants to make use of this for religious reasons to make sure that the ancient Norse religion never goes away, so he's aiding the old Norse to settle in America.
I can't think of a good way of getting past the need to explain. I can't think anyone would not want to know what was going on it in Fay's position. I put it off as much as possible, but they'd reached a stage where it was going to be hard for anyone to talk about anything else.
Sorry this didn't work for you, but thanks again for reading.