Alive (in hiding)
The Voice is mentioned in the beginig of book two at Jack's sisters tanning salon, when a mysterious woman dropped a cell phone. (It's specifically designed for him because the phone runs on Michael's electricity, meaning only he can answer it.) Michael picked up the phone for her and asked the woman if it was hers. She answered, "No, Michael, I think it's yours" and gave him instructions on what to do. Michael goes to the back room of the salon and receives a call on the cell phone, from what they begin to call 'the Voice'. He tells Michael they- their organization has been following their progress and that they're going to need help if they want to stand up to Hatch. Michael decides to (vaguely) trust the Voice and do as he says. The Voice tells him that the police are on they're way to arrest Michael for burning Jack's house down, even though in reality it was the Elgen.
Michael tells the others what the Voice said and also that they left cars for them at a different spot. The Voice had also mentioned to Michael that in the salon they were trapped and they had to leave, as there was only one exit. Michael follows his instructions until they find the Safe House the Voice left for them along with wads of money.
Later, when the Elgen find their Safe House and kidnap the teens back, they escape and manage to blow up two of the three vans. They miss the third van but somehow it blows up on it's own. The Voice tells Michael that it was their organization helping, discreetly so the Elgen would think that the teens had just blown that one up as well on their escape. It is said that the Voice wants to keep an anonymous cover so the Elgen cannot trace them.
Near the middle of the book, the Voice calls Michael again when they are at Jack's friend Mitchell's house, for a rest. He tells Michael that he has a van parked on their street and they spotted the Elgen coming down under the false pretense that they are checking for radiation in the neighborhood. They go from door to door with scanners hoping to read that electric children are inside. The Voice also tells Michael that if they have any GP's with them (Jack and Wade) to get rid of them or get the tracking devices out of their arms that the Elgen implanted. .
Near the end of the book, the Voice gives Michael an iPod Nano so that when they play a certain song by Colby Cross they will come to pick them up once they've escaped the Elgen compound. Tanner and the rest of Electroclan make it out but Michael is separated from the rest of the group
The Voice then sends one of their agents, Jaime, to pick up Michael and get the newly-discovered glow Tessa to safety. The rest of the Electroclan were captured by the Peruvian government. Michael wishes to rescue them, against the Voice's wishes. The Voice eventually comes around though, and arranges passage for the complete Electroclan to Cuzco, and then Lima. There Abigail, Zeus, Tessa, and Ian make a decision- they are leaving the Electroclan. The Voice flies them out to one of their bases in Nicaragua, officially giving The Voice custody of six different glows. Though, the number drops back to two when they decide to return to Peru to help in the sinking of the Ampere. At the end of the book, the Voice gives Michael and the rest of the Electroclan a new mission- find and rescue Chinese child prodigy Lin Yulong, who who has been captured by the Elgen, because she has the smarts to figure out how the MEI works.
The Voice is not directly heard from in this book, but Joel and Ben, two of their agents, guide the Electroclan through their mission to rescue Jade Dragon. It is mentioned that most of the agents of the Voice have never seen the Voice in person. When their ranch is destroyed, The Voice goes even deeper into hiding than they were before, and refuses further contact with the Electroclan.
Storm of Lightning
The Voice was in hiding for most of this book. Although he is guarded by the 16th Glow Cassy, whom he orders to retrieve Schema to talk directly to the voice. Schema knew who the Voice was, but said, "Impossible. This is impossible. How could it be you?”
Fall of Hades
The Voice is Identified as Dr. Coonradt. However Cassy lets it slip that there may be someone in a higher position than The Voice.
The Final Spark
Hatch uses Zara, the 17th glow to read Cassy's mind to see where the Voice was located. Hatch later captured the Voice and found out where Carl T. Vey was.Then the Vey family was reunited.