Instead of its usual twin bill, the U.T. gives birth to triplets tonight. Rex Harrison's latest picture, even better than his muchly-touted "Night Train," is having a local premiere preparatory to a national publicity campaign. As in the earlier thriller, the plot concerns espionage and counter-espionage in World War II; but there's twice as much gunplay and the sets have been done on a more extravagant scale.

The star, veddy veddy British and the perfect personification of the rest of the world's picture of a Harvard man, succeeds in making a fantastic plot seem real. A bit bogged down at the start by a desultory script, Harrison in his final scenes, where he outraces a time-bombed munitions train, had even hard-boiled reviewers from the Hub dailies perched on the edge of their seats. Different, well-acted and exciting tonight's "sneak peecture" may well, like its predecssor, become one of the hit movies of the year.