Princess Twilight Sparkle finds something familiar inside her castle, and it's Human Twilight's spectrometer. She puts it on before Delta arrives to see her. He lets Twilight show it to her friends, but he realized that the device could gather magic and he will explain this to Sunset Shimmer.

Twilight Sparkle voiced by TwilitWing (Kalyn)
https://www.youtube.com/user/VioletxWing

Delta Brony voiced by DaWillstanator
https://www.youtube.com/user/DaWillstanator

MLP by Hasbro