ten
o'clock
`` Yes . '' `` There 's a small door in the boundary wall which leads out to the railway line . '' `` Well , what of that ? '' `` Suppose that door to be left open , would it be an impossible thing for a crazy woman to slip out through it , and to be run over by the ten o'clock express ? '' `` If she would only get in the way of it . '' `` You do n't quite catch my idea yet . Suppose that the express ran over the dead body of a woman , would there be anything to prove afterwards that she _ was _ dead , and not alive at the time of the accident ?