Agree with Lucertola. Has Everyman suddenly decided we've had it too easy for too long? LOI 1d seems very tenuous to me (if I've got the right answer), definition of 24a seems wrong (should be understand, not prepare), 15a and 17a both tricky, which in turn makes 13d, err, challenging, 18a is surely UK specific. Thank goodness the SE corner provided a bit of relief - by the time I got down there I was fearing the worst!