Mark Johnston is one of Britain’s leading racehorse trainers, having become the first Flat trainer to send out more than 200 winners in a season (2009), a feat which he has, to date, repeated in 2010, 2012, 2013, 2014, 2015, 2017 and 2018. On August 23, 2018, Mark became the winningmost trainer in British racing history when he saddled his 4,194th winner. This film tells the story of Mark and Deirdre Johnston from the very start of their racing career to becoming record-breakers.