The story is told by Desiree, who is a middle-age woman who has constant epilepsy and can't walk or talk. But even though she is paralyzed physically, she is very smart and has a gift which basically lets her possess other living creatures and use their bodies. Well, after her mom gave her up as a kid, she took in three foster kids named Christina, Margareta, and Birgitta. Desiree thinks that one of the three girls lived the life that was meant for her. Using other people's and birds' bodies, she sends each of them a letter which she says will put them in motion towards some plan of hers.
My prediction is that whatever Desiree's plan is will start to unfold. I also think that I will learn more about each of the girls' past.