You can read through the chapters to get an idea on
where this story is going.

Pre-Arc: The Beginning that Ends with you - Science - Done!
Prologue 1: Ravier Connor α - Done! - D
Prologue 2: Simulation - Ravier's Beta Test - Done! - C+
(The first portion has been shifted over to Extra...)

Arc 1: Maseria - The Pawn - Science - Done!
Chapter 1: Chance Meeting? - Done! - B
Fragment 1: Beginnings - Done!
Chapter 2: Test Phase I - Done! - E
Fragment 2: The Case - Done!
Chapter 3: Solar Inverse - Done! - B+

Arc 2: Athena Ray - My Friend! - Magic - Done!
Fragment 3: The 'Gap' (Part 1: Trapped) - Done!
Chapter 4: Roots (Part 1: Mana Raizen) - Done! - B
Fragment 3: The 'Gap' (Part 2: Mire) - Done!
Chapter 4: Roots (Part 2: Cyrus Aria) - Done! - B
Fragment 3: The 'Gap' (Part 3: 'Gap') - Done!
Chapter 5: Disappearing Act - Done! - C
Fragment 4: The End - Done!
Chapter 6: Apocalypse Infection - Done! - C+
Chapter 7: Revert ~ Athena Ray - Done! - A

Chapter 7.5: Ace - A++ Done.