When Emma Fitzgerald said she needed a break, she didn't mean in the time continuum. After losing her boyfriend to her mortal enemy, Emma heads to Granny's house for the summer to do some good old fashioned sulking. When she wakes up, she (and her phone) have somehow traveled back in time to the year 2004.

Her uncle, who is a teenager now, warns her not to do anything that could alter the future. But then an unexpected encounter results in all evidence of her mortal enemy vanishing from her phone. Texts, photos—everything. She no longer exists.

Emma wonders if the Universe sent her back in time to save her own broken heart. But then her best friend's texts disappear from her phone, too. The disruption to the time continuum had repercussions. If Emma wants to save her best friend, she'll have to save her enemy first.