Endangered Essence

What happened to Leah?
Why didn't Chriton recognize Leah as his Conversance when he first saw her?
What is the depth of the connection between Leah and Malachi?
How can Leah be Chriton's Conversance and still love Malachi as deeply as she does?
What happens when one person is physically drifting away, another is mentally locked away, and the third is spiritually expiring away? 
Are they strong enough to stand by each other despite the heartbreaking hardships they are forced to endure?