Complex sentence: In a moment of crisis, Zach deserts Vicky at a nearby hospital on the island, because the nauseating smell of the hospital reminded him of his time spent there, both during his time with rheumatic fever, and after his suicidal attempt.
Split into simpler sentences: In a moment of crisis, Zach deserts Vicky at a nearby hospital on the island. He did this because the nauseating smell of the hospital reminded him of his time spent there, both during his time with rheumatic fever, and after his suicidal attempt.