midnight
All three of them left the house a few minutes later . * * * * * There was little sleep for anyone at the Stanlock home that night . The mystery of the patched-up letter , coupled with Helen 's apparently voluntary disappearance and the fear that she had been led into a trap of some sort , in line with the threat contained in the skull-and-cross-bones letter , kept everybody up until long after midnight . Meanwhile , Mr. Stanlock called up the police station and asked the lieutenant in charge to come over and begin work on a new angle of the strike developments . `` One of the girls has disappeared , and we are afraid that something serious has happened , '' he told the officer over the telephone . The latter soon drove up to the house in an automobile and was admitted by Mr. Stanlock .