[step] into the breach
1
to take action or assume responsibility in a difficult or challenging situation, often when others are unable or unwilling to do so
The idiom "step into the breach" comes from military terminology, where a "breach" referred to a gap in a defensive position. It has been in use since at least the 16th century. Today, it is used to describe a situation where someone takes over a difficult task or responsibility in a crisis or emergency situation.
- He stepped into the breach and saved the company from bankruptcy.
- I'll step into the breach and take over the project.
- If the boss doesn't show up, I will have to step into the breach and run the meeting.
- She is stepping into the breach and leading the team during the crisis.