A London couple have reached the Scottish Highlands in a challenge to document all 2,563 railway stations in England, Scotland and Wales. But what set Vicki Pipe and Geoff Marshall on such an epic journey?
The two railway enthusiasts are nearing the end of their project to create an online documentary.
The adventure has already seen them spend three months on trains and station platforms. All going well, they should reach their final destination this weekend.
So far, the Highlands leg of their journey has taken them to somewhere special - the Glenfinnan Viaduct, which famously appeared in the Harry Potter films.
"I have to say that was very cool," says Vicki, after crossing the viaduct. "For any Harry Potter fan you just think about the journey to Hogwarts."
She adds: "That was brilliant. I didn't say anything for a few moments."
For Geoff, crossing the viaduct prompted other thoughts.
"It made me think about the men who built the Glenfinnan Viaduct," he says.
Looking out the window into the rain that is falling, he adds: "Those men would have had to be out in all weathers."
Vicki and Geoff decided to attempt their station-bagging venture because of a shared passion for railways.
For Geoff, it also fits with his interest in completing challenges.
He has twice set a fastest time record for travelling to every London underground station.
Vicki says: "My passion comes from the social history of railways and an interest in the communities around railways.
"That's what I do at the London Transport Museum. I work with communities to understand how railways impact on people's lives."
Planning the journey using all the different routes involved has been labour intensive.
The couple also had to agree to set themselves a rule on what to do at requested stops.
Trains do not always stop at these sites because no-one asks to get off or on, but the couple have documented these smaller stations by taking videos and photographs as they pass through them.
"The journey has also been about engaging with our fellow humans," says Geoff.
"That for us has really been what the journey has been about.
"We have been asking people how they use trains, what they think of them and would they use them more."
The couple hope to reach the final destination in their months-long project on Saturday when they are scheduled to reach Wick.
And how will they get back home to London?
They will be taking the train. Of course.