The Twins' Mystery Teacher (Sweet Valley Kids, No. 3)

Whos Mr. Marshall? Elizabeth and Jessica Wakefield are identical twins who sit side by side in their second-grade class. When their teacher is out with the flu everyone changes seats and the substitute teacher cant figure out who anyone is -- especially Jessica and Elizabeth! Thats when the new substitute teacher arrives. Mr. Marshall is very strict and the class is on its best behavior. Then the twins see Mr. Marshall getting into a police car. Could he be a dangerous criminal? When the class finds out who he really is they are in for a big surprise!