by hook or by crook

using any method possible Templeton was recruited to obtain the formula by hook or by crook.

if you intend to do something by hook or by crook, you are determined not to let anything stop you doing it and are ready to use any methods I decided that I was going to get that job by hook or by crook.

By whatever means possible, fair or unfair.

By any means necessary to accomplish the purpose; one way or another. Several explanations for this phrase have come down over the years. One is that it refers to two Irish towns, Hook Head and Crook, through which Oliver Cromwell tried to capture the nearby city of Waterford. Another is a medieval custom of allowing villagers to collect for firewood any loose branches that they could pull down with a long-handled curved implement. A third explanation is the most plausible: shepherds rounded up their flocks by means of a crook, a long staff with a curved end. A shepherd would chase after a reluctant ram, ewe, or lamb and hook it with his staff by any means . . . by hook or by crook.