Some times the train drives in other time the tunnels swallow it. Its so amazing each time the train roars to life and finds it way down the imaginary track into her tunnel. Slowly sometimes, other times with lightening speed. Isn't it amazing how the walls close around his train and swallow it whole I don't know why he hits reverse only to ram back in again. But i know the result is it makes her moan and ask him to do it again. Over and over it continues they go back and forth. Causing the mechanical mechanisms spew forth lubricants to cool the heated engine . . . OMG is what they scream