four o'clock
Hence they took turns at propelling the boat and soon Laurie was as much at home on the pillows in the stern as he was in his wheel-chair . He greatly enjoyed the smooth , jarless motion of the craft ; and often , even when it was anchored at the float , he liked to be lifted into it and lie there rocking with the wash of the river . It made a change which he declared rested him , and it was through this simple and apparently harmless pleasure that a terrible catastrophe took place . On a fine warm afternoon Mr. Hazen and Laurie went over to the shack to meet Ted who usually returned from work shortly after four o'clock . The door of the little camp was wide open when they arrived but their host was nowhere to be seen . This circumstance did not trouble them , however , for on the days when Laurie was expected Ted always left the boathouse unlocked . What did disconcert them and make Laurie impatient was to discover that through some error in reckoning they were almost an hour too early .