There's a 'ghost train' service running in and out of London Paddington. It is rarely advertised and attracts few riders. It runs to and from West Ruislip, once a day, on weekdays only.
This 'parliamentary' train is a little-known service kept open only to stop the lengthy process of shutting the line down completely due to lack of use. This means that if you ever have a need to get between Paddington and Ruislip at somepoint mid-morning, there is a train service that just might be suited to you.
We took a ride on it, to see what happens.