IC2218 from Cologne to Hamburg - which one of my fellow passengers is the most likely murderer?

Whilst my arrival into Cologne was delayed by about twenty minutes, the DB Lounge was very comfortable, and had wi-fi, thus the postings earlier. However, time waits for no bureaucrat (except if tea is involved, naturally), and I had a connection to make... which was running fifteen minutes late from Stuttgart - so much for this German efficiency I hear so much about.

The train pulled in, only to reveal an unexpected treat - six seat compartments. Better still, I had a window seat for my four hour journey to Hamburg. My fellow passengers looked relatively normal, a smartly dressed man in a suit with an orange tie and a laptop to my left, a man wearing a semi-ironed white shirt reading some papers covering in evidently small print from the way he was holding them close to his face, and a woman who had clearly decided to colour-coordinate with the train (yes, more grey, I fear) enlivened by a teal striped scarf. Even her eyes were a steel grey/blue. It seemed that we were all travelling individually from the lack of conversation.

The train was scheduled to stop in Dusseldorf, Duisburg, Essen, Bochum, Dortmund, Munster, Osnabruck and Bremen, before calling at a series of Hamburg stations, leaving me plenty of time to enjoy the facilities, including the bistro car. Even better, the bistro car comes to you, and a very nice man brought me a beer with which to enjoy the ride.

At Dusseldorf, we were reduced to just the lady in grey and I, and I felt relatively safe, so I put some madrigals on the Kindle Fire, and read for a bit as we headed through the Ruhr Valley. At Dortmund, we were joined by a husband and wife, probably in their sixties, and who seemed quite harmless, so I sipped my beer and listened to some Brahms trios whilst I basked in the sun. It was all very pleasant.

The German scenery - a bit flat (so unlike my dear Suffolk) - passed by before, almost before I knew it, we were in Hamburg, where my next break was scheduled. A short cab ride and I was safely ensconced in a very nice hotel room...