Set in a world where science fiction tropes exist as everyday realities, Charles Yu's 2010 novel How to Live Safely in a Science Fictional Universe traces a time traveler's quest to find his father. Because the journey at the novel's center is so _______, with the protagonist ricocheting chaotically across time, the reader often wonders whether the pair will ever be reunited.

Which choice completes the text with the most logical and precise word or phrase?