Z contracts to carry a cargo of Y's wheat on Z's ship from Galveston, Texas to Jeddah, Saudi Arabia for a flat rate. The contract does not specify the route, but the voyage would normally be through the Straits of Gibraltar and the Suez Canal, a distance of 9,000 miles. A month later, and several days after the ship has left Galveston, the Suez Canal is closed by an a container ship running aground in the Canal, so that the only route to Jeddah is the longer 12,000 mile voyage around the Cape of Good Hope. Z refuses to complete the voyage unless y pays additional compensation Must Y pay Z additional money?