In order to explain the effects of high speed movement on observations of length and time many textbooks on special relativity propose a train moving at a constant speed slightly less than the speed of light.  A passenger on the train makes some measurements of an event. The event is something happening such as measuring the time taken by the passenger to pass between two markers on the railway embankment (a term used by Einstein on page 25 of his book Relativity, the Special and General Theory, Methuen, fifteenth edition 1952).  An observer at rest on the embankment measures the time interval taken by the event. Do their results agree? Who is correct, the passenger or the observer on the embankment? Hop aboard for our ride on the Einstein express!