Exposing too much of the hidden plumbing of metaphor, reference and allusion in a certain kind of novel is equivalent, as far as I can see, to “spoiling” the plot of a mystery. The reviewer’s job is perhaps to suggest where to look for the pipework, although even that needs to be done with restraint: you have a duty of care to the reader’s sense of personal discovery. Besides which, there are novels so rotten with reference that to acknowledge, let alone pursue even the more obvious instances would mean a four thousand word review consisting solely of page numbers, quotes and references of the reviewer’s own. Fun, but no one is going to publish–or read–it, and nor should they at that stage. It’s a process best left to someone further along, to another kind of commentator. A review is a first response. Of course, not giving the game away can sometimes make reviewing more difficult; but things are tough all over.