I myself, am an amateur scientist, so naturally when offered to go on an expedition to take samples from an active volcano I accepted, although falling in and waking up in a new world as a burning horse no less was not what I was expecting.
When Twilight Sparkle was killed in the changeling invasion all of Equestria mourned. But when a mysterious figure in armor slays Chrysalis in front of the princesses they will learn that anyone can change. For better or worse.