The train set off in the wrong direction – or rather we had joined the west-bound train to Hawaii via Texas, rather the service heading east.

We managed to alight at the first stop in rural Colorado, where it was snowing. As TPR wandered up the platform to check for a service that would take us to our final destination, I searched through my suitcase to find some warmer clothes.

Suddenly I sensed a presence behind me. I turned to find a greasy-looking man observing me as I pulled on a grey jumper. He asked me questions about the US citizenship test, but I knew that his real intention was to attack me.

How loud could I scream, and would TPR hear my call for help?