Zada and Zora lived in Stain'd-by-the-Sea and were the servants of Ignatius and Doretta Knight and knew Cleo Knight ever since she was a baby, having taken her home from the hospital after her birth. Cleo is noted as the only person who can tell them apart, and they prominently raised her. Cleo learned several Italian cooking terms from them when she was young.
A few weeks before Cleo's disappearance, the family received a private apothecary, Dr. Flammarion. The Knight parents started to get disoriented and confused, which made Cleo feel very lonely. Ignatius and Doretta then began preparations to leave town.
Cleo has breakfast with Zada and Zora, eating her usual breakfast of Schoenberg Cereal, before going to her room. She requests that the twins take her photo, and then leaves to meet a friend she doesn't name. When Cleo does not return, Zada and Zora are very worried. Dr. Flammarion tells them not to call the police, as Cleo probably just ran away- though the sisters are convinced she would have left a note- and so instead they hire S. Theodora Markson and Lemony Snicket to investigate.
When they arrive, Theodora promises to do her best to find Cleo, while Snicket requests details. The servants let them in, where they pass by the Knight couple and Flammarion in order to get to the kitchen; most of the house is packed up for the move.
Zada and Zora serve cinnamon rolls to their guests, where they explain about Flammarion, and that they will leave when the Knights do, as they have no other choice, even if it means leaving Cleo behind. They take the investigators to Cleo's bedroom, where Snicket finds a failed invisible ink experiment.
After the investigators leave, Ignatius and Doretta give the order to leave town, and Zada and Zora leave with them, forced to abandon Cleo. In another town, they recieve news that Cleo is safe, and they celebrate with "something delicious."
Zada and Zora are briefly mentioned by Cleo, who remembers them teaching her cooking terms. She tells Snicket that she hopes her work will bring them back to town.