There's no other way to start this story: the cat came back.
The cat in question is Polly, a tabby from Plymouth, England. She belongs to a retired rail driver, and she ended up riding the rails in the undercarriage of an inter-city train for two full days after badly breaking her leg.
According to This Is Plymouth, Polly is thought to have climbed onto the high-speed express train near her home.
Train manager Emily Mahoney-Smith discovered the cat after hearing her meows during a stop in Cornwall. She found the cat in a sealed unit - according to Mahoney-Smith, Polly could only have got in while the panels were removed for maintenance at a depot near her home.
According to First Great Western, the company that operates the train, "the cat had been stuck on board for some time. We've calculated it did at least 1,667 miles (2,683 km)."
When Polly was found her paw was badly wounded, and she was hungry and thirsty from two days without food or water, but Mahoney-Smith says "she was in surprisingly good condition and her coat was very shiny."
She took the cat on board the train and fed her some tuna from a buffet sandwich, and then alerted the RSPCA, who got in touch with vet Matthew Berriman.
Examining the cat and her injuries, Berriman says he assumed she was a stray, and was preparing to put her down.
Luckily, he thought to check whether she had a microchip implant that would identify her as belonging to someone. She did.
Polly had disappeared from home about three weeks earlier. Her owners, 84-year-old retired train driver Arthur Westington and his wife Louisa, 82, thought she was gone for good, until they got a call from Berriman asking permission to amputate Polly's damaged front left paw.
The operation was a success, and the cat is recovering at the vet's office near Penzance, UK. She's expected to return home in a few days.