"The Avalanche: A Mystery Story" by Gertrude Franklin Horn Atherton is a romance and mystery story set in San Francisco in the early days of the 20th century. Shortly after the great earthquake shook the state, Price Ruyler, an accomplished businessman, marries the young French Helene Perrin. However, married life isn't all that it seems. While Helene grapples with boredom, Price finds himself embroiled in a mystery that involves none other than his mother-in-law.