Trixie has wings and a horn, but she isn't a princess yet. With Equestria's political situation fragile following the events of Tirek's attack and subsequent defeat, she has to hide her status from everypony. At the same time she has to learn how to control these new powers and try to earn the respect she desires.

Of course this would all be easier if there wasn't someone working against her from the shadows.

You don't need to read The Unchosen One before you read this, but since this is a direct sequel it would be good so you know how and why Trixie got those wings. It would also be good to have seen the ending of season 4. If you haven't yet, don't read the bit above where I mention Tirek. Don't read that last sentence either.