Trace Voltiere is an earth pony with an affinity for engineering. He designs, builds, and maintains a lot of mechanical and electrical devices for the many ponies in Ponyville. Today however he encounters somepony he did not expect when assisting in the renovation and setup of Twilight Sparkle's castle into the new library for Ponyville. Meanwhile, PInkie Pie discovers that she has a love of projectors and moving pictures and she also discovers a shocking secret about somepony she holds very dear to her heart.