about three
o'clock
`` Then there 's the woman -- the servant , Lena Kraus . '' `` She goes to the roof every Wednesday while the Hoffs are away to signal . Other days they apparently do the signalling themselves in some way we have n't caught on to yet . She always goes up about three o'clock and -- '' `` Suppose she comes down unexpectedly and catches you ? We ca n't have that happen . That would put them on their guard . '' `` She wo n't surprise us .