From Amazon: As if 17-year-old Alexandra Lucas’ anxiety...

From Amazon:  As if 17-year-old Alexandra Lucas’ anxiety disorder isn’t enough, mysterious holograms suddenly appear, heralding the end of the world. They bring an ultimatum: heed the warning and step through a portal-like vertex to safety, or stay and be destroyed by a comet that is on a collision course with Earth. The holograms,claiming to be humans from the future, bring the promise of safety. But without the ability to verify their story, Alex is forced to consider what is best for her f...