about nine o'clock in the evening
`` Oh , yes -- Helen and Burdon Woodward . Well , I 'm glad she 's going out with Wally today . She 's safe enough with him . '' It had been arranged that Wally should drive Helen to Hartford to do some shopping , and they were expected back about nine o'clock in the evening . But nine o'clock , ten o'clock , eleven o'clock and midnight came -- and still no sign of Wally 's car . `` They must have had an accident , '' thought Mary , and at first she pictured this as a slight affair which simply called for a few hours ' delay at a local garage -- perhaps the engine had overheated , or the battery had failed . But when one o'clock struck , and still no word from the absent pair , Mary 's fancies grew more tragic .