Thanks to some perceptive reviewers on goodreads I'm giving this one another look after it whooshed over my head the first time. I'm reading the 1973 hardback edition without Garner's introduction. This is one of those books that needs context for its three stories.
Updated: I got far more out of the stories' allusions this time round, as well as more appreciation of Garner's super laconic prose. However, in terms of retelling the Tamlin story, Jan/corn goddess girl/Margery are pale and passive substitutes for the tale's Janet.