"Not unless they had a shift change she didn't tell me about."
It's quite likely they won't even be missed until shift change.
"I was going to give them a call at the top of the hour," he said, "just after the shift change."
And the shift change of activities toward the study area.
Show up for the shift change, usually happening around 8pm.
When the shift changes, the night guys can't find it.
At 6 am, there was a shift change in the control room.
Another hour or so until shift change at the police station.
The shift change was every two hours, which kept the men fresh.
It was two hours too soon for a shift change.