One of those that needed a bit of sleeping on it to come together properly - I was too much otherwise occupied to complete by midnight this week, and like dr b found it took ages to make the first, rather tentative grid entry which is still the one I don't fully understand even if it can't be anything else.
Especially with the short words there is plenty of room for error, not least because Hypnos is (I hope!) very oblique sometimes. This led me, at one point, to think the quotation omitted everything except the first couple of words, since my (plausible) alternative letters didn't fit anything I recognised from my schoolday remembrance of the theme.
Really good crossword, lots of PDM's, proper Listener fun.