For a while I thought this book was called The Janus Connection because, as thematics go, the link to our friend Janus is about as tenuous as they come. Not getting it, Trevor, not getting it. Of course I did take the thought a bit further. It made me think of the Wizard of Oz and the wicked witch of the west, but that is presumably a pecadillo peculiar to me. To the book.
Conjunction is the one to read.
If not, then you might be thinking how on earth this book ever got comissioned at all. There is probably an underlying subtext in there somewhere. It's that ol' faithful - if colonisation is either horrific death or barley corn then just hand me a plough and let me get farming. Of course having the Doctor along is a bonus. But not if it is Baxendale's Doctor.