Read the following excerpt: "The stillness of the night was interrupted only by the occasional rustle of leaves in the brisk wind, an ambiance both tranquil and foreboding. The figure paused before the ancient, gnarled tree, its roots sprawling like the fingers of a hand reaching out from the earth, a silent witness to the passage of time. In the dim light, the air felt thick with the weight of unspoken memories, as if the night itself held its breath, waiting for the inevitable dawn."
In this context, the word 'foreboding' most nearly means: