Observed from a distance, the edifice of science appears impressive - a robust and coherent body of knowledge. However, tiny cracks become visible if one looks closer. Unexpectedly, and drastically, these cracks become chasms. The whole monumental structure of knowledge falls apart like a house of cards. These fault-lines appear as soon as one inquires about the true nature of reality. - Unexpectedly, and to everyone's great dismay, the Book of Nature turned out to be an incomplete translation. The original appears to be written in an alien language, incomprehensible to the human mind, encompassing vastly greater knowledge. Nonetheless, the Book of Nature uncovers enough insights into the workings of reality to allow human ingenuity to engineer technology. But apart from offering fragments of knowledge, it is stubbornly silent, or outright inconsistent and paradoxical, when it comes to the true nature of things. Space, time, and matter transcend any human conceptuality. We are left with a make-shift and incomplete ontology of reality. The borders of our knowledge open up to an abyss of ignorance.