Betty's top secret Galactic Guardian diary is seen when she accidentally brings it to school in Power of the Pharaoh. The diary contains memories from Betty's past missions. At first she was lucky that nobody saw it until it flies out of her hands and in front of Penelope, who wanted to read it very badly. The diary was locked and Penelope refused to give it back to Noah whom Betty asked to get the diary back. Penelope tried to open the locked diary with a straw and pliers. When Betty got back, Penelope finally got the diary unlocked and read the secrets out loud. Penelope was convinced that everything in the diary is just a fiction story. Everyone thought those stories were interesting and they wanted to hear more.
It reappears in As the Worm Turns!.