ThestoryconcernstheWaterburyfamilywhomoveto"ThreeChimneys",ahouseneartherailwayafterthefather,whoworksattheForeignoffice,isimprisonedasaresultofbeingfalselyaccusedofsellingstatesecretstotheRussians.Thethreechildren,Roberta(Bobbie),PeterandPhyllis,findamusementinwatchingthetrainsonthenearbyrailwaylineandwavingtothep..ddd