The Four Feathers by A.E.W. Mason

"Three more days." Both men fell asleep with these words upon their lips. But the next morning Trench waked up and complained of a fever; and the fever rapidly gained upon him, so that before the afternoon had come he was light-headed, and those services which he had performed for Feversham, Feversham had now to perform for him. The thousand nights of the House of Stone had done their work. But it was no mere coincidence that Trench should suddenly be struck down by them at the very moment when the door of his prison was opening. The great revulsion of joy which had come to him so unexpectedly had been too much for his exhausted body. The actual prospect of escape had been the crowning trial which he could not endure.

"In a few days he will be well," said Feversham. "It is nothing."