Harry Potter

From the text:

Harry now turned to his present and unwrapped it. Inside was what looked like a miniature glass spinning top. There was another note from Ron beneath it.

Harry —this is a Pocket Sneakoscope. If there’s someone untrustworthy around, it’s supposed to light up and spin. Bill says it’s rubbish sold for wizard tourists and isn’t reliable, because it kept lighting up at dinner last night. But he didn’t realize Fred and George had put beetles in his soup.
Bye — Ron