Set twenty-two years after Storm of Secrets.
Reading trhe Summary of Storm of Secrets is recommended but this hyper summary will brief you on everything you need to know -

World:

1. Most alicorns are mortal unicorn/pegasi with an average amount of magic. There are six cosmic forces that require an Alicorn to steward them, and when one steward dies another takes over, becomes immortal, and gains a large but non-ridiculous power boost.

2. MQ is a measure for a unicorn's raw magical power. An average unicorn had 100 MQ. Unicorns with more than 400MQ are referred to as Alpha Unicorns. Twilight 636, Celestia 1220.

Plotline:

1. The Everfree Forest is bigger on the inside than the outside. The deeper levels include multiple hives of changelings and monsters called Terrormongers who can create illusions, feed off fear, and are being held at bay by a secret Equestrian army corp called Everfree Rangers. (Details unimportant.)

2. Rainbow Dash is married to a Ranger veteran named Silent Storm.

3. Zecora is a martial art master; and has trained elite rangers for years, including Shining Armor and Silent Storm.

4. Shining Armor has gotten a massive boost to his power, and now has an MQ over 1800.

5. Cadance is Luna and Celestia's niece! Her mother is Celestia's half-sister who stewards the oceans and rules the island Queendom of Oatlantis.

There will be satellite stories linked in the authors notes of various chapters; read them if you want a fuller picture of what's going on. Some of them have less obvious connections, then others, but they are all relevant; particularly Forsaken and Celestia's Smartypants.

I almost rated this story mature. This is not a clopfic or a gorefic, but there are a lot of serious issues including things like rape, torture, suicide, addictions etc. Consider the story to have a lot of mature content, not juvenile content. I don't claim to have all the answers about everything I touch on; but I hope I've at least asked the right questions, in a way that will make people think.