Take a story's temperature by studying its tone. Is it hopeful? Cynical? Snarky? Playful?
A Disinterested Observer
What else can you really say about a narrator who watches all ten people on an island without about as much interest as you watch the Olympic curling qualifiers? The characters may gasp and moan when people start turning up dead, but the actual tone of the writing is matter-of-fact:
He was in the little washhouse across the yard. He had been chopping sticks in preparation for lighting the kitchen fire. The small chopper was still in his hand. A bigger copper, a heavy affair, was leaning against the door- the metal of it stained a dull brown. It corresponded only too well with the deep wound in the back of Rogers’ head. (11.57)
Only too well, don’t you know? Even describing Rogers’s gruesome death, the novel is all “just the facts ma’am.” It doesn’t seem queasy or uncomfortable with the gruesome scene; in fact, it doesn’t seem to care much either way.