Great journeys usually begin with a thriller. For Aimée Crocker, the late-19th-century railroad heiress and pioneering journey traveler, the thriller arose when she was only a small baby. According to Crocker’s 1936 memoir, And I’d Do It Again , 1 night within the late 1860s or early 1870s, she bounded up the steps of her California dwelling forward of her nanny to find a shock. In her room, bathed in silvery moonlight, a ghostly girl lay on her mattress, wearing magnificent silk robes and a gossamer veil in contrast to any apparel the younger woman had seen. (She later realized it was the costume of a Hindu noble.) The girl checked out Crocker and smiled. “She seemed to know me,” wrote Crocker many years later. “It was someway…I can hardly clarify it…as if I knew her, too; as if she had been there naturally, as if she belonged to me.” Unafraid and excited, the woman known as for her nanny to come back see, however the apparition vanished. The breathless caretaker scolded her, how...