Adam and Jules have been married for twenty-five years when they discover a time machine in their shed—can it bring back their romantic spark? Or will it unravel everything? Written by a real-life couple who fell in love while writing their bestselling debut novel twenty-five years ago.

One couple. One past. A million tomorrows.

Meet Adam and Jules. Married for nearly twenty-five years and stuck in a rut, their future looks, well, boring.

Then Adam stumbles across a box of old mixtapes he and Jules made for each other when they were young and falling in love. He dusts off his vintage stereo, inserts one of the cassettes, presses play … and the unbelievable happens.

With the power to travel back in time, he and Jules can revisit pivotal moments in their pasts. Is this the key to getting their sparkle back? They embark on an epic hunt through the multiverse for their perfect love story. But as they visit the past and recapture the headiness of falling in love, they realize that traveling across time could be as dangerous as it is addictive, because the temptation to change just a few small things is irresistible. As the ripple effects spiral out of control, can they find a way back to their messy and imperfect, yet glorious, real life? Or will they lose each other forever?