When a regular girl must travel through time to save her brother from an alien invasion, high-stakes action enters an endless loop. In Merrie Destefano’s Valiant, Sara knows only one thing for certain: if her brother dies, the world ends. So she repeats the same day over and over, attempting to save him in a new way each time and watching him die again and again until the time portal breaks and she’s given one final shot. Some rushed action and thin character development at the outset make the story difficult to get into, but once this story ramps up, it’s a thrilling read, with plenty of unexpected twists, a surprise ending, and pressing questions that demand a sequel.

Best for: Young adults who enjoy fast-paced action, aliens, time travel, dystopia, and futuristic technology.

Discern: Lots of violence and gore, open portrayal of drugs and drug use.