Within the Space of a Second (The Mark of the Time Traveler) by Elise Helliwell

A slow-burn, swoon-worthy love story about two people separated by time and the dangerous secrets that threaten to tear them apart. A debut time travel romance for fans of The Seven Year Slip, Divine Rivals and A Discovery of Witches.
 
Limited copies with sprayed edges available for pre-order! 
 
Every morning, Mariella Adams wakes with a strange electrical energy buzzing beneath her skin. Terrified she has inherited her late mother’s mental illness, she tells no one. But when Mariella discovers her mother’s lost journals with an entry dated after her death, she’s desperate for answers.
 
The mystery only deepens when Mariella is approached by two strangers, Rose and Parker, who claim to be time travelers from the future. They say that interfering with the past – and Mariella – is forbidden, but they need her help to restore Parker’s ability to time travel before they’re caught in this timeline.
 
Shocked, Mariella agrees to help them. After all, they might hold the answers she’s looking for. And the more time she spends with them, the more she finds herself drawn to Parker. As she fights to uncover the mysteries of her past and the secrets of his future, will Mariella discover the truth before time runs out – and Parker disappears forever?