3.5 
 Originally posted at Vampire Book Club 
 In Dissonance Erica O'Rourke imagines an alternate world, known as the Key World. This is attached to alternate worlds, known as Echoes, which form and branch off of the Key World depending on the varying choices made in everyday life by the Originals (people like you and me) that inhabit the Key World. 
 Walkers are people who, as theirs names suggest, are able to Walk between these differing Worlds. Walking is genetic and even though Walkers mix in with Originals in everyday life, they are pretty much a society unto themselves. Governed by The Consort, the purpose of Walkers is to preserve the Key World first and foremost. To do this they move undetected into Echoes to repair any breaks or tune any dissonance to keep them from bleeding out into the Key World. 
 Sixteen year old Delancey Sullivan is the youngest Walker in her family, and is no stranger to breaking the rules. She has a natural talent for Walking and would rather spend her time between Worlds than in her everyday life going to an Original school where she goes unnoticed by everyone. During one of her unsanctioned Walks, Del runs into an Echo of her longtime crush Simon Lane. Being reckless, Del sees no harm in talking to the Echo (a big no no), but during other Walks, Del begins to notice Simon's Echo more and more. Things get further complicated when Original Simon remembers little details about Del that only his Echo should remember, if Echoes were supposed to remember that is. When things become increasingly out-of-whack with the Key World, how far is Del willing to go to protect her secrets? 
 Erica O'Rourke has created one of the most interesting worlds/concepts I've read about in quite awhile. I loved the imagery that the Key World is like the trunk of a very big tree and the Echoes are like branches. I further loved the connection O'Rourke made with music theory in how everything has its own frequency and signal sound. I think Erica O'Rourke has set up a world with so many possibilities, that this series could branch off (no pun intended) into so many different stories/directions in the future. I would love if that happened. Although I won't lie, sometimes the imagery was a little difficult to follow; you just have to persevere with the terminology. 
 With that said, Del was a mess. Her knowingly reckless actions throughout the whole story made it really difficult for me to be on her side. She kept digging herself further and further into a hole and was too stubborn to stop and look at the possible destruction her actions could cause. All for a boy. This is a rare case where I wasn't really interested in the romance. I really wanted Del to be stronger than her crush on a boy that didn't even know she existed until a couple weeks ago. Erica O'Rourke tries to incorporate a conspiracy theory about The Consort and all the information they're not telling the Walkers. All Del's mistakes only made The Consort's rules look legit and overshadowed any disdain I was supposed to feel towards them. 
 Towards the end, once revelations are made and secrets are revealed, I did become interested in where book 2, Resonance, will go. Ending on a cliffhanger, I'm hoping these events caused Del to grow up a little bit to consider what actions she'll take next.