She gave you everything. But what does she want in return? When Lizzie's daughter Meg is given a life-saving heart transplant, Lizzie feels hugely grateful to the nameless donor. Then she receives a letter from the donor's mother, Karen, asking to meet, and it seems like the least she can do. But as soon as Karen is welcomed into their lives, Lizzie feels something isn't right. And before long, she can't help but worry that by inviting Karen in, she might have put Meg in danger . . .