"Euston, remember? I thought you'd prefer to walk. Rather than go down in the Underground again."

She said she would have preferred to have got the Tube.

We proceeded on in convoy, at a glacial pace, me ten yards out in front, her stopping every 30 or 40 seconds, suspicion mounting. 

So I threw everything I had at it: "We just have three more roads to cross"; "See that tower, we'll be able to see the station from there"; "We're three-quarters of the way there" — before eventually resorting to: "Andrea, you're gonna have to trust me." 

Finally, we reached a point in the pavement where Euston's blessed rail sign came into view. 

"Look! Look! See that sign? What does it say?"

"London Euston."

"Yes!"

"I'm sorry," she said, emanating relief. "I'm sorry."

Andrea promptly sat down on a bench. 

"I have to eat. I haven't eaten all day."

"OK, OK, take your time. Get some food down you."

She swigged from a bottle of Coke, unwrapped a sandwich.

"Have half."

"No, no," I countered, unpeeling my own banana. 

Heading towards Euston, my plan was simple: to identify the "authorities" as quickly as possible, settle Andrea's nerves, get her on the right train if it's the last thing I did. 

Result! Outside the station I spotted two police officers standing next to a homeless man. 

"Officer!"