one
o'clock
He would have been perfectly happy to have braved her indignation for a single glance at her face . He walked back , lighting his pipe . Who could she be ? What peculiar whimsical freak had sent her singing past his window at one o'clock of the morning ? A grand opera singer , returning home from a late supper ? But he dismissed this opinion even as he advanced it . He knew something about grand opera singers .