Catherine is the triplet sister of Gideon and Luke, but looks unlike them in appearence. She is described as being quite pretty, and Lisa calls her "touchy-feely". She is the main antagonist of the last four books. She has an American accent, due to living in America. She is quite mad, and has moved from family to family, following multiple "accidents" that they have (she caused them).
In Running the RiskEdit
In Running the Risk, she is introduced to the Colas, and makes friends with Gideon and Luke. Her powers appear to be a little of everything, and as her powers increase, all the Colas become lethargic, and less powerful. Dax and Lisa realise that she is a parasite (she can use other people's powers), and confront her. She admits it and promises she will stop.
However, she manages to drain all the Colas powers, by getting them to hold hands, and attempts to kill them all, but fails, as Luke stops her. She also traps Dax in a cage, and Lisa in the gate house. Despite all the other colas being saved by Luke, he and Catherine are in the end the ones incinerated by Catherine's evil plan. They are believed to be dead
In Going to GroundEdit
In Going to Ground, she returns, and begins to retaliate against Gideon. She burns down electrical pylons, scorching into the ground beside them a letter "G". When the points are placed on a map, it shows that she has been following him.
When Gideon confronts her she appears to be a hovering ball of electricity. She tries to kill him but fails. Gideon recognises it as her and insists that she and Luke are still alive
In Dowsing the DeadEdit
In Dowsing the Dead, Lisa begins to dowse for Catherine and Luke, on the request of the government, who, although they find it hard to believe Catherine and Luke survived, accept that it could have been Catherine's spirit. Owen and Gideon go off to look for them in holland, where Lisa is sure that they are. But, with the help of the wolf, they discover that they are in fact alive and in France, in a windmill. There she has been keeping Luke, near to death, making him mute and drawing the energy out of him.
When they confront her, she attempts to kill Dax, by pinning him, as a bird, to the windmill by his wings. In a final confrontation they find Catherine happily burying her brother alive in the middle of the woods. They think that they have killed her, with a gunshot to the chest, but when she is in the helicopter going home, she manages to take some of Mia's healing power, healing herself. She pretends to still be dead, but uses her stolen telekinetic powers to bring the helecopter down. She then pretends to be a French citizen, convincing the French officials that she should be taken with them rather than going back to Britain with the COLA group.
In Stirring the StormEdit
In Stirring the Storm, she works with some of France's and Britain's high up government men to kidnap the colas and auction them off to other countries. They have tracking chips implanted in their heads that are designed to block their powers and explode if they misbehave. The people she works with misjudge her power and unpredictability and in a final showdown she dangles Dax's dad (Robert Jones) and Owen Hind off an oil rig, and forces him to chose which one to save.
It can be assumed that because of her death, the powers of the Colas who lost them due to her will get them back.