Into the Highlands

We came up Thursday on the Caledonian Sleeper, an overnight train from London that starts off as one lengthy train and then splits into Highland and Lowland sections overnight. I am very fond of trains; when I was ~8 we had a family holiday in Europe with a lot of trips via couchette sleepers, and I found them absolutely fascinating (bunks on a train! Odd thick paper sheets! train design instantly familiar when I saw it again in a volume of From Eroica with Love, of all things) and so I really wanted to give my kids their own no doubt equally odd associations.
( Lengthy digressions. )