Puzzle complete, I think, but can anyone please parse for me 15d - Undefined number carried by rail, coming in to a scheduled terminus (15) t-a-n---d, which I take to be TRAINLOAD. Also, for those who've done the puzzle, can anyone explain to me the use of solution to 16a - STAGE - in several clues? (Except for 6d where it's perfectly clear). Many thanks.