For fans of Raina Telgemeier and Kayla Miller comes the second graphic novel in the funny slice-of-life Cool Code series. When the coding club finds that their app has a malicious user, Morgan, Zoey, and Daniel code an update to contend with a mischievous llama avatar who\'s guiding a not-so-popular kid named Marcus to cause chaos in the school. Annoying little siblings, chaotic pranks, and more abound as they race to repair the glitchy app-and their own friendships-in their school before the damage is irreversible. (W) Deidre Langeland (A) Sarah Mai