Mike Chen brings us an epic love story—in a time loop. When strangers Mariana Pineda and Carter Cho get stuck together repeating the same four days, finally reaching Friday might mean having to give up the connection growing between them.

A cozy sci-fi novel from the New York Times bestselling author of Star Wars: Brotherhood

The only thing harder than finding someone in a time loop is losing them.

Grieving her best friend's recent death, neuroscientist Mariana Pineda’s ready to give up everything to start anew. Even her career—after one last week consulting at a top secret particle accelerator.

Except the strangest thing happens: a man stops her…and claims they've met before. Carter Cho knows who she is, why she's mourning, why she's there. And he needs Mariana to remember everything he’s saying.

Because time is about to loop.

In a flash of energy, it’s Monday morning. Again. Together, Mariana and Carter enter an inevitable life, four days at a time, over and over, without permanence except for what they share.

But just as they figure out this new life, everything changes. Because Carter's memories of the time loop are slowly disappearing. And their only chance at happiness is breaking out of the loop—forever.