In "Farming Like the Incas" by Cynthia Graber, she explains what made Incan farming so remarkable. They successfully farmed in the Andes, which are considered "some of the tallest, starkest, mountains" and were able to harvest on terrain that is steep and difficult to move on. They were able to overcome climate difficulties by building terraces, irrigation systems, and cisterns.
The article lists many ways in which the ancient Incas were productive farmers despite living in the rough landscape of the Andes, a rocky and desolate mountain region. While modern farmers have had difficulty farming in the region, traditional Incan farming methods remain successful even today. Incan farmers grew specific plants that were well-suited to the Andes. Also, the use of terraces, canals, and irrigation techniques allowed Incan farmers to maximize efficiency, which enabled their empire to grow. -Edmentum or Apex answer
Surreptitiously, as described by Merriam-Webster, is "done, made, or acquired by stealth." Essentially, it's doing something sneakily or in a stealthy way.
because Rainsford must decide for himself if he will accept the general's challenge, face Ivan, rejecting the challenge, or find a way to escape "Ship-Trap Island."
