Captain Shannon by Coulson Kernahan

Here was a pretty kettle of fish! For the first desperate moment wild thoughts of pulling the connecting cord and stopping the train peeped in my brain like the mad faces seen at the windows of an asylum. But as the mad faces vanish at the return of the keeper, so in the next moment wiser counsels prevailed and I was considering the situation with the seriousness which the facts demanded.

And first I had to ask myself what could be the red-bearded passenger's motive for booking to London, and then suddenly changing his plans and getting out at an unimportant country station? Could it be that he was indeed James Mullen, and that he was at his old tricks of covering up his tracks?