Set between Rainbow Rocks and Friendship Games.
When Shadow Runner and Overburner were little kids a man named Solas kidnapped them and performed an experiment which resulted in them gaining magic powers. Years later they both escape from him and are now on the run, trying to get as far away as they can. With Solas and four others he performed the same experiment on coming after them they find that their best possible chance of escape is the portal at Canterlot High.