In Sir Walter Scott's novel "The Bride of Lammermoor" after the death of Lucy, the hero and his horse suddenly disappear into a bog of quicksand. One minute he's here, and the next he isn't. I am fatally attracted to quicksand and become all happy when it creeps into a story. For instance, Peter Wimsey almost sinks forever into quicksand in "Clouds of Witness".
They didn't try to put quicksand into Lucia di Lammermoor, but if the heroine in Kat'a Kabanova can jump into a river, why not into quicksand?
Today, 10/04/05, the New York Times includes an item on what quicksand really is. I love this. Except, according to the article a horse and rider couldn't suddenly disappear into it. I liked thinking they could.