eleven o’clock
`` With so much time upon your hands , Dr. Whiles , '' the Prince remarked , `` you can scarcely fail to have arrived at some reasonable explanation . '' `` I do n't know whether it is reasonable or not , '' the doctor answered , `` but the obvious explanation is getting on my nerves . There are two things which I can not get away from . One is that I can not for the life of me imagine your riding a bicycle twelve or fifteen miles north of London between eleven o'clock and midnight ; and the other -- '' `` Come , the other ? '' the Prince remarked encouragingly . `` The other , '' the doctor continued , `` is the fact that within half a mile of my house runs the main London and North Western line . '' `` The London and North Western Railway line , '' the Prince repeated , `` and what has that to do with it ? ''