"I...I...should... but" April stopped her sister from speaking with her finger leaving a little gray mark of dust on her lips."Don't say a word, its o...k come here" April said as she smiled at the little gray mark on her sister’s face. Stephanie moved closer to her sister looking deep into her eyes, now managing to stop the tears from falling onto her soft red cheeks."I love you too Steph" April smiled; Stephanie could see that April meant the words they had been the closest of all the sisters.. She ran up to her room, leaving her things in the car. She ran upstairs to her room and closed the door. She saw all the pictures of her and Alex. One had Alex standing behind her, helping her grip a bat, his crotch against her butt. She wondered how many times her brother used her to get himself off. She threw the picture on the floor. She sat on the floor with her back against the queen-sized bed, sobbing.Looking up, Colby saw her reflection in the mirrored sliding closet door. She hated her. Tenderly, he bent to kiss her neck. She reached back to pull his head tighter to her throat. She had already broached the boundaries set by the last time. Like last night, he found her small breast and gently kneaded, rubbing her nipple to hardness. Baby, he breathed in her ear. Daddy, she whispered. Please. He knew she was asking him to abate some her need. He knew she was on the edge and it would take just a few strokes to make her cum. But he wanted her to wait until Friday when they could. In it men and sometimes women are injected with Ruk serum and become serum girls, creatures one step away from perpetually in heat slavegirls.Zhorian science allows people to remain young and -- usually -- healthy for centuries, and to take on the body of any other by use of serums. Ruk's Serum was an adaptation of this process. It was created by a bio-chemical genius whose paymistress and director was the slaver Vanora. Legend says that Vanora was miffed at the idea that it was always women.