Crimson — K.J. Dahlen

When Serenity gets sick while she's pregnant, the doctor treating her reveals that her blood type is battling the baby's blood type.Sergi calls in Levi as he is the blood expert.Levi finds she has a rare blood type, one she got from her father. There is no one left from her father's family to give them any answers and no one wants to even contemplate the alternative.In the meantime, Slave Sellers have decided they want both Serenity and her sister Serena. So they stupidly try to come in to go through the Btava and get them.