Aluminum Company of America (ALCOA) (plaintiff) agreed to provide Essex Group, Inc. (Essex) with its long-term needs for aluminum. The price for the aluminum was based upon a formula that would allow a portion of the price to escalate in accordance with the Wholesale Price Index (WPI). The contract provided a maximum price that Essex would pay in the event the WPI caused the price to escalate excessively. After some time, ALCOA’s costs increased substantially and the price provided in accordance with the WPI was not sufficient to cover those costs. ALCOA filed suit, seeking reformation or adjustment of the contract. ALCOA argued that it was entitled to relief under the doctrines of frustration of purpose and impracticability.