From Longman Dictionary of Contemporary Englishsquare onesquare onePROGRESS#the situation from which you started to do somethingbe back to/at square one The police are now back at square one in their investigation.go back to square one (=used when you start something again because you were not successful the first time) Okay, let’s go back to square one and try again.from square one I’ve had to relearn the game from square one. → square
Examples from the Corpus
square one• Arms races sometimes culminate in extinction, and then a new arms race may begin back at square one.• He was back to pounding nails again, back to square one for the eighth or tenth time.• We are back to square one.• Never shut the filter down, or the beneficial bacteria will die and you will be back to square one.• If something didn't break, and soon, they would be back to square one.• After the next break Sally is moved to go back to square one.• Richard told me he felt like he was back to square one. 