Phoebe is at dinner with Jason. Paige orbs in and asks for Phoebe's help. They orb to Piper, who is hiding in an alley from a manticore. Paige orbs a power line onto the manticore, electrocuting it. They then find its baby lying nearby. The baby has a long serpent's tongue.
Wyatt is taken with his new friend, to Piper's displeasure. Piper tries to separate them, but Wyatt just orbs to the other baby's playpen or the baby shimmers into Wyatt's. Piper suspects the baby is evil, Paige knows he's still a kid, he can be swayed between good or evil, and Phoebe can sense neither good nor evil in him. Chris is unhappy and wants the baby vanquished, but Piper, despite her misgivings, is unwilling to do it.
Phoebe has told Jason that she loves him. The next day, she finds Jason in a meeting and that he's flying to Italy. She thinks he's avoiding her. Darryl calls Paige regarding a hostage situation. The SWAT team moves in. Paige casts a spell to render Darryl bulletproof. He walks toward the gunman, who fires three shots, but the bullets bounce off Darryl's chest. Darryl comes out with the gunman in handcuffs and trashes a police car trying to put the gunman in the back seat.
Chris orbs to Leo and tells him about the demon baby, who seems as fascinated with Wyatt as Wyatt is with him.
Phoebe again tries to separate Wyatt and the demon baby, but the baby gives a manticore cry. Shortly after, a beast shimmers into the attic. The beast attacks the sisters and Wyatt raises his defensive bubble. He grabs Piper and shimmers away.
The beast tells Piper that he wants the baby. Piper slips free of the rope binding her wrists and blasts him. The beast demands the baby again, and threatens to kill Piper if she does not help him get the baby.
The baby screams again and a manticore shimmers in. Phoebe throws a potion and vanquishes it. Two more shimmer in, but the beast shimmers in behind them. He kills the manticores and shimmers away with the baby. Leo and Chris agree to return the baby to the manticores, but the baby is missing.
The beast is injured; Piper is tending his wound. He tells her that he's not a demon; he's the baby's human father. He had used potions to assume a manticore-like form so he could find the baby. Paige and Phoebe, unaware of this development, go to the manticores. They then orb to Piper and the father and the manticores shimmer in after them. They throw potions, but Piper blasts them. The sisters orb away, but Piper tells them about the father. The father, nearly dead, morphs back into his human form. The sisters call for Leo and he heals the father.
The sisters grab potions and go back to the manticores, who now have the baby. Piper plays peek-a-boo with the baby, encouraging him to shimmer to the sisters. They throw their potions and vanquish the manticores. They return the baby to his father, who happens to be known as Derek. Jason cancels his flight to Italy so he can be with Phoebe.