This nice malaphor was heard on Season 1 Episode 2 of Cold Case Files; “Killing on Christmas Eve”.
22:39 into episode. Video is below. It’s a congruent conflation of “back to square one” and “ground zero”, both meaning starting place or at the beginning. This is a bookend of a previous posting, “starting from ground one”, posted in 2012. https://malaphors.com/2012/11/07/starting-from-ground-one/. Both idioms have numbers – zero and one – contributing to the confusion. many thanks to Mike Ameel for hearing this one, sharing it, and sending me the video to prove it! This is not fake news, folks.