How To Wash A Cat  is by Rebecca M. Hale. Set in San Francisco, California’s historic Jackson Square the story includes an antique shop, hidden doors, old tunnels, and two cats. It is written in the first person and we know the main character as “Oscar’s niece”. When Uncle Oscar dies unexpectedly his niece inherits his antique shop. When she starts exploring the various items and curios in the shop she finds that many of his former associates are unusually interested in the shop and its hidden secrets. As part of her inheritance she is given a strange key, a puzzling map tucked away in a book and she finds a trap door in the store that leads to an underground tunnel connecting many of the old buildings. As she follows the clues she must unravel a trail of deceitfulness that starts in the shop and leads back to the gold rush days of California.