the Riddler's townhouse. When there, Catwoman sees that Ivy has been keeping the Riddler under mind control so that she and Harley could use his townhouse as a hideout. Here, Catwoman decides that with Gotham City more dangerous than ever with all the gang wars and a new Batman, a partnership with the other two women would be advantageous. However, Ivy fears that Catwoman has lost her edge and prowess, and consults with Zatanna on the nature of Catwoman's injuries. Zatanna responds that Catwoman has psychological wounds that would need healing. Ivy resolves that she and Harley would provide Catwoman with "positive female reinforcement". The three then agree to become a team. However, Harley and Ivy have one condition that Catwoman is to reveal to them Batman's secret identity. Eventually, Ivy and the other Sirens ambush the Riddler at his office (with Ivy using her plants to truss and gag his secretary), telling him that they've been framed for the murder of a young nurse. He agrees to help clear their names, and during the discussion Ivy reveals that she has recently taken up a job at the Gotham division of S.T.A.R. Labs under an assumed name (Dr. Paula Irving). She is eventually kidnapped and placed in a specialized containment unit by a researcher named Alisa Adams, but escapes and turns the table on her captor by binding her with vines. Ivy initially informs Adams that she plans to kill her, but instead decides to let her live after seeing a photograph of Alisa's young daughter. Ivy then threatens Alisa into keeping her mouth shut about her true identity, telling her that she will change her mind and kill her if she reveals her secret to anyone. When Harley Quinn betrays her friends and breaks into Arkham Asylum with the goal of killing the Joker, she ultimately chooses instead to release Joker from his cell, and together the two orchestrate a violent takeover of the facility. Poison Ivy arrives and tries to convince Harley Quinn that the Joker is evil, but Harley Quinn refuses to believe her and knocks Poison Ivy unconscious. After they are defeated by Catwoman and Batman, Catwoman then tells Poison Ivy that they are no longer friends, after Ivy had drugged Catwoman in an attempt to discover Batman's identity. Poison Ivy is taken to Arkham Asylum. Ivy soon escapes and ambushes Harley in her cell, binding