Kloe is a clone of The Mastermind .
Kloe attended the SKUL acedemy with Zoe when she was younger. Zoe uses Frank's genetic tracer to track Kloe down. Kloe was found in a burgled house hiding in the wardrobe. She was taken back to Saint Hearts where it was discovered that she was the one who broke into the house. It is also revealed that SKUL had genetically modified her DNA rendering her unstable; causing her to become easily angry, aggressive, and violent. Angry because she wasn't allowed to join M.I.9, she kidnapped the Grand Duke and demanded a ransom for his life. At the end of Series 6 she was rescued by M.I.9 and admitted into a medical facility so her genetic damage could be repaired.