On 1 December 2021 Labour and Plaid Cymru signed a Co-operation Agreement committing the parties to working together on 46 different policies in the Senedd - ranging from Senedd reform to free school meals for all primary school children. Three years on, James Williams looks back at how the agreement came together and what it achieved with two guests who were at the heart of the negotiations that sealed the deal. David Davies was a special advisor to the then First Minister Mark Drakeford. John Osmond was his Plaid counterpart for Adam Price and has turned his experience of being in the room into a new book, "The Politics of Co-Opposition"