This is the fourth film in the series to feature the antics of the troublesome schoolgirls created by Ronald Searle.Made some six years after The Pure Hell Of St Trinians,this Launder-Gilliat collaboration has a topical theme (the real Great Train Robbery had occurred only a few years before) and was also the first to be made in colour.However,despite the presence of a talented cast (including the return of series regulars George Cole and Richard Wattis)and an exciting beginning,the script soon descends to the level of tiresome farce with the protracted three way chase on the railway neither entertaining nor funny.Frankie Howard,as the part-time barber and jewel thief,isn't given enough to work with and only Dora Bryan sparkles as the two-timing, tango-loving headmistress.