The Aftermath - The Impact Series, #4

Lured to a strange hotel populated by stranger guests, Tia unwittingly finds herself at the center of a conspiracy. It's been almost five years since a wrathful extraterrestrial called Rex perpetrated a mass shooting that caused hundreds of millions of people to take their own lives. The world has mourned its losses and moved on, trying to adhere to The Pledge to save themselves from more violence.
But when a solar storm conceals the dangerous activities being done at the hotel, Tia must figure out who these strangers are and what they are doing before the shooting's anniversary. Are these strange and beautiful people adhering to The Pledge? Or are they creating their own violent and nefarious rules in order to change the world? Tia has only days to determine whose side they are on-not to mention, whose side she is on-but first, she must stay alive.