Cascade — Lisa Tawn Bergren

Critically wounded during a battle in Waterfall (Book 1 in the River of Time series), Gabi is making her way through her recovery when she figures out she is being poisoned. The only way for her to be saved is to travel back through time to modern culture -- and modern medicine. But after she and Lia leap back to the present, she finds herself suffering from no more than a broken heart. She convinces her sister to return.

When they do, they discover that summer has become autumn in 1332, and that all of Siena longs to celebrate the heroines that turned the tide in the battle -- and every man in Florence would like to see them dead. Still, love remains for Gabi and Marcello as they strive to make it through each day and discover what the future might hold for them. For Lia, love blossoms for the first time with Marcello's charming cousin Luca, and her own future becomes more complicated.

In the midst of the plague beginning to spread from village to village -- a plague that they know will ultimately kill more than a third of Siena's people -- Gabi must discover if Lady Rossi is truly as treacherous as she believes, escape the Florentines who seeks to trade her for hard-fought land, and decide if she's willing to promise her heart to Marcello forever...and leave her mother behind for good.