step into the breach
US /stɛp ˈɪntu ðə briːtʃ/
UK /stɛp ˈɪntu ðə briːtʃ/

1.
assumir o lugar, intervir, preencher a lacuna
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.
Quando o ator principal adoeceu, seu substituto teve que assumir o lugar.
•
The volunteers had to step into the breach when the regular staff went on strike.
Os voluntários tiveram que intervir quando a equipe regular entrou em greve.