When substitute teacher Zarand Szilard is awakened by a last-minute call to cover Ms. Salas's classes at Stony Estancia High School, his gut alerts him to expect trouble. By the first period, his worst fear materializes: a student discovers Ms. Salas's lifeless body. Zarand's intuition tells him it's murder.

As a substitute, he has no standing with the school or the police. Regardless, he uncovers plenty of motives. Ms. Salas investigated college admission fraud at the high school. She solicited harassment complaints against the principal. She knew about the infant grave discovered on school grounds. She distributed condoms.

While investigating her death, he discovers she is not Ms. Salas. To find her killer, he also must uncover her true identity.

How can Mr. Szilard unravel these mysteries within mysteries when the school and the police want to close the case before someone sues?