Waiting on Wednesday: Passenger by Alexandra Bracken

Waiting on Wednesday is hosted by Jill over at Breaking the Spine. This meme spotlights upcoming releases that I'm eagerly anticipating. ---

Passenger

Passenger #1 Alexandra Bracken Expected Publication: January 5, 2016 Genre: YA Time Travel

Violin prodigy Etta Spencer had big plans for her future, but a tragedy has put her once-bright career at risk. Closely tied to her musical skill, however, is a mysterious power she doesn't even know she has. When her two talents collide during a stressful performance, Etta is drawn back hundreds of years through time.

Etta wakes, confused and terrified, in 1776, in the midst a fierce sea battle. Nicholas Carter, the handsome young prize master of a privateering ship, has been hired to retrieve Etta and deliver her unharmed to the Ironwoods, a powerful family in the Colonies--the very same one that orchestrated her jump back, and one Nicholas himself has ties to. But discovering she can time travel is nothing compared to the shock of discovering the true reason the Ironwoods have ensnared her in their web.

Another traveler has stolen an object of untold value from them, and, if Etta can find it, they will return her to her own time. Out of options, Etta and Nicholas embark on a perilous journey across centuries and continents, piecing together clues left behind by the mysterious traveler. But as they draw closer to each other and the end of their search, the true nature of the object, and the dangerous game the Ironwoods are playing, comes to light -- threatening to separate her not only from Nicholas, but her path home... forever.

It has time travel. My question: why do they need Etta to find this object of untold value? Why do they need to snatch someone from the future?