Sky was back again as the undercover agent at her school. The last mystery she solved had been about the missing lunch money. 

Sky sits in her science class, listening to her teacher talk about chemical reactions.

In the library, Sky's friend Sophia is reading a book. When Sophia sees Sky, she calls her over.

Hey Sky! 

Hi Sophia!

Sophia has a new case for Detective Sky! What could it be?

Someone is cheating off my tests but I don't know who it is! 

Don't worry Sophia! I will find out who this mysterious cheater is!

The next day, Detective Sky is back in her science class. Today they were taking a test!

Sophia whispered some exciting news to Detective Sky when the test was over. 

The person cheating off me is someone in this class! I felt them staring at my paper but I couldn't figure out who it was!

Hmmm interesting

Detective Sky thought long and hard about what to do next. The only answer she could come up with was to wait for the next test and watch to see who was looking at Sophia's test.

Sophia, we have to wait for the next test so I can tell for sure, and then we'll go to Miss Smith and let her know so that it doesn't happen again.

Okay I trust you Sky!