twelve
o'clock
That was like Mark Gifford . He was nothing if not careful and precise with regard to everything of a business kind . Then she began asking herself the sort of rather futile questions people do ask themselves , when puzzled , and made uneasy by what seems an inexplicable occurrence . How would Mark get to Darnaston by twelve o'clock to-day ? Surely he could only do so by starting before it was light , and motoring the whole way from London ? She gazed at the words `` very private . '' What did they portend ?