the calm before the storm
idiomPart ofcalm
the calm before the storm — idiom
1. a quiet period that happens just before a time of trouble, conflict, or intense
1.idiom
Definition
a quiet period that happens just before a time of trouble, conflict, or intense activity — suggests that the peace will not last long.
Example
The office was strangely quiet on Friday, but everyone knew it was the calm before the storm of the Monday deadline.