step into the breach

US /stɛp ˈɪntu ðə briːtʃ/
UK /stɛp ˈɪntu ðə briːtʃ/
"step into the breach" picture
1.

挺身而出, 填补空缺

to take action when another person or group is unable to, or to fill a gap in a difficult situation

:
When the lead actor fell ill, his understudy had to step into the breach.
当主角生病时,他的替补不得不挺身而出
The volunteers had to step into the breach when the regular staff went on strike.
当正式员工罢工时,志愿者不得不挺身而出