Being sisters is never easy. But when you're as different as Sarah, Cassiopeia, and Lucille, it's even harder! The first is haunted by recurring dreams, the second lives with her head in the clouds, and the last spends most of her time with her cat. Then one day they discover a mysterious photo of their mother pregnant. Where was it taken, and who is the baby? And most importantly, why was this photo hidden away in the depths of the attic? To find out, they'll have to venture into the tangled forest of the Grémillet family secrets!