Each of the six quartets of initial letters of the Across clues reveal DCLL which equals 750. When correctly arranged, the unclued lights reveal ‘Doc’s seven hundred and fiftieth crossword’. The title ‘Thousa’ is three-quarters of 1,000 which is 750. First prize Gerald Daly, Ockendon, Essex Runners-up Barbara Flook, Meareway, Glastonbury; Alistair Macnab, Hastings