Sanctuary by Lisa Appignanesi
When investigative journalist Isabel Morgan disappears, colleagues and lovers see this as just another gambit in an ever-dramatic life. But her closest friend, Leo Holland, is filled with a sense of dread- something terrible has happened to Isabel. She is more certain of this than of much else in a life that is teetering close to the edge. In desperation she flies from New York to London to try to trace the woman she realizes has become her sustaining force. But how well does anyone know their best friend? Convinced that Isabel's analyst holds the key to her disappearance, Leo masquerades as a potential patient. In the process, however, she discovers more than she set out to know. Danger, it seems, in Isabel's secret world, comes in many guises.