What's happening- Chapter 1

This story is a what if story line inspired by Chicago Fire season 2 finale and season 3.
What if Shay didn't die. What if Gabby and Shay didn't trade places in time. This is something that is going to affect the whole house. How will Matt take things? Is Shay gonna be okay? Most importantly Will Gabby survive?
What will happen?

All the characters belong to Dick Wolf and the writers of Chicago Fire and Chicago PD!