The Island of Dr. Moreau has a classic horror ending going for it. The protagonist escapes from the horrific place, survives the frequent attempts on his life, and ultimately reaches safety. And just as soon as he lets his guard down, the minute he can breathe, bam, the horror reappears and the story ends. Only the horror returns in a far subtler way than Jason Voorhees jumping out of a closet or Freddie Kruger popping up in your dreams.
Prendick returns to London, expecting to be free of the horrors of Moreau's island. Unfortunately, as he walks through the crowded streets, he cannot
"persuade [himself] that the men and women [he] met were not also another Beast People, animals half-wrought into the outward image of human souls, and that they would presently begin to revert,—to show first this bestial mark and then that." (22.5)
Prendick has recognized that the horror of Moreau's society is the horror of all societies. Its members are born of beasts; civilization is only a magic trick meant to hide this truth. And when he sees society this way, "[he] look[s] about [him] at [his] fellow-men; and [he] go[es] in fear" (22.5). Like all classic horror movies, this is the twist ending, the big "gotcha" moment. The Beast People aren't gone; they're hiding in civilization's closet like a bogeyman.
So, Prendick moves to the country to live his life in peace. There he reads books, studies chemistry during the day and astronomy at night. He does this because he thinks it must be "in the vast and eternal laws of matter, and not in the daily cares and sins and troubles of men, that whatever is more than animal within us must find its solace and its hope" (22.7). This is the small light at the end of the dark tunnel, and oddly it seems to echo Moreau's reasoning from earlier in the novel.
Moreau sought the eternal laws of nature through the creation of man as man currently is. Instead, Prendick is looking toward the stars and away from the planet to seek his answer. So, while it may be the same question that drives them, their methods are completely different. And, sometimes, the method really does make it all the difference between horror and hope.