Mahlon Bollinger and his wife, Vinetta Bollinger (Bollingers) (plaintiffs), executed an agreement with Central Pennsylvania Quarry Stripping and Construction Company (Central) (defendant) which permitted Central to deposit construction waste on their property in the course of its work on the nearby Pennsylvania Turnpike. The Bollingers believed, pursuant to a mutual understanding of the parties, that this contract contained a provision which required Central to first strip off the topsoil, then put the construction waste on the bare ground and then cover it with the previously removed topsoil. Although Central initially adhered to this layering process, after a period of time it discontinued the process. When the Bollingers complained, Central told the Bollingers that there was nothing in the contract which required it to follow this layering process. Central told the Bollingers that the equipment for removing topsoil had been taken away and that Central was incapable of complying with the original understanding. The Bollingers then commenced an action in equity requesting that the contract be reformed to include the provision allegedly omitted by the parties’ mutual mistake and that the contract, as reformed, be enforced. The court granted relief for the Bollingers, and Central appealed.