Throughout Penny's life, her relationship with her father hasn't exactly been a close one. Penny is about to turn sixteen and she is determined to have the best birthday ever. Penny and her friends audition to become back-up dancers for Fifteen Cent, cousin of Sticky Webb. Fifteen Cent begins to develop romantic feelings for Penny and she reciprocates her feelings for him, the two share a kiss, causing an infuriated Oscar to look on. Oscar grounds Penny and he doesn't allow her to have her birthday, causing Penny to furiously disown Oscar for treating her like a child and for being her father. Trudy tries to get Penny and Oscar to make peace, by taking them on a tropical vacation, but Penny doesn't seem to be enjoying the trip and she befriends Cashew, a sympathetic peanut clone of Dr. Carver. However, another plot begins to unravel for Penny, when she uncovers Dr. Carver's true motives and she learns that the family she went home with isn't her actual family, but clone versions of them. Penny enlists the help of her friends to save her real family from Dr. Carver.