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4.0 6
by Paul Blackwell

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A shadowy figure. An intense roar. The sensation of falling—fast.

That's all Callum Harris remembers from his tumble over the waterfall. But when he wakes up in a hospital bed and finds his best friend trying to kill him, Callum knows something is seriously wrong. Unfortunately for him, the mysteries are just getting started.

Why are his


A shadowy figure. An intense roar. The sensation of falling—fast.

That's all Callum Harris remembers from his tumble over the waterfall. But when he wakes up in a hospital bed and finds his best friend trying to kill him, Callum knows something is seriously wrong. Unfortunately for him, the mysteries are just getting started.

Why are his parents acting like he's some big sports star all of a sudden? And why are all the buildings in town more run-down than Callum remembers? Worst of all . . . what happened to Callum's brother? Either Callum has gone seriously crazy or something happened when he went over the edge of the falls. Something impossible. Callum needs answers, and now. Because in this twisted new version of the life Callum knew, his former best friend isn't the only one who wants to see him dead.

Editorial Reviews

VOYA - Margaret Capobianco
When Callum wakes up to find himself lying in a hospital bed, he has no idea what happened or how he got there. Apparently, he has jumped off a waterfall in the town of Crystal Falls and no one knows why. As Cal tries to put the pieces of this confusing puzzle together, he learns the life he woke up to is far different from the one he remembers. First of all, his parents, who were on the verge of divorce, seem happily married; the most popular girl at school, who never liked him, is visiting him on his sick bed; and his brother is paralyzed from an accident, from which Cal remembers his brother walking away. Callum seems to have awoken in some kind of alternate universe and wants to get back to his normal life as soon as possible. Teens who enjoy suspenseful books will want to pick up this new thriller the next time they visit their local library or bookstore. This novel is thoroughly enjoyable and takes the reader on a great journey as Callum tries to discover what happened to him when he went off the waterfall. The author makes the story a page-turner and the ending leaves the reader hoping we will be able to return to Callum's world again. Reviewer: Margaret Capobianco
Kirkus Reviews
A potentially deadly trip over a waterfall turns out to be the least of teenage Cal's problems. Callum "Cal" Harris has survived the falls, a journey few others have. But the town of Crystal Falls in which Cal wakes to find himself is vastly different from the one he remembers. Cal is feared at school, he has a hot girlfriend, his best friend seems to hate him, and his beloved older brother is comatose. Struggling to adapt to this new reality, Cal feels hunted by an unknown presence that seems bent on thwarting his attempts to fit in. Blackwell's debut for teens attempts to explore the concept of the multiverse, how the past shapes the present and the perception of reality, but it does none of it well. There's no narrative tension, no character development and no compelling reason to turn the page. Callum is an incessant whiner, which is understandable given that he has jumped universes and woken in completely new circumstances, but it also makes it difficult to generate any sympathy for him or his plight. While the multiverse has potential as a narrative device, Blackwell simply falls into the tired evil-twin trope and leaves it half finished. The framework never jells, leaving the plot points suspended in the mist of the falls themselves. (Thriller. 14 & up)
Toronto Star
“Blackwell writes with a crisp, clean style, keeping up suspense and providing nicely off-kilter elements in character and detail.”
“A menacing, suspenseful thriller. Hand this to fans of Mary Pearson’s The Adoration of Jenna Fox (2008), Michael Grant and Katherine Applegate’s Eve and Adam (2012), and the novels of Neal Shusterman.”
Bulletin of the Center for Children’s Books
“A pure concept thriller…the riveting opening and intense final scene will keep genre fans satisfied and breathless.”
“Thoroughly enjoyable. A page-turner.”

Product Details

HarperCollins Publishers
Publication date:
Product dimensions:
5.80(w) x 8.30(h) x 1.20(d)
Age Range:
14 Years

Meet the Author

Paul BLackwell never went over a waterfall himself, but he has jumped off a sixty-foot cliff. Once was enough.

This is his first book for teens. He lives in Montreal, Quebec.

Customer Reviews

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Undercurrent 4 out of 5 based on 0 ratings. 6 reviews.
Anonymous More than 1 year ago
Well-written, great characterization, snappy dialogue.  Though Callum whines throughout the book, it it understandable given his plight. I really enjoyed this book. It kept me turning pages. I hope the author is writing another book. 
Anonymous More than 1 year ago
Good book. Not bad for a first time teen book from this author. The story was just good enough that leads you in a thriller/mystery adventure. I thought the amount put into the story was just good enough, not too much things happening yet not lacking much. Def. recommend this book if you want something quick to read. :)
Anonymous More than 1 year ago
Mainly becase it was told from a males POV so thats really cool also, its way more believable because he makes stupid choices and isnt living a perfect life. I really like how Cal was ligitimently scared and confused for practicly the whole book. If it was me in his place i would probably go totally crazy and try to get my parents to move my whole family to some other country, so he handled it really well. The only thing that would make it better was if he did freak out a little more in the beginning, then it would seem more relistic, but you should defintly buy this book
BuriedUnderBooks More than 1 year ago
From beginning to end, Undercurrent is a puzzle, starting with Callum waking up in a world that's just not quite right. It's the little things that seem off at first but then the problems begin to mushroom. Most horrifying is his discovery that his brother, Cole, who's a jock and a bully, now lies paralyzed and Callum has no idea what happened to him. Callum begins to realize that people don't even know him by his "real" name---they call him Cal---and that he is suddenly one of the popular guys and, yet, some people want him dead. Why? Even his dog doesn't want to be around him. And why is his dad living at home again? Why do classmates Willow and Bryce treat him so oddly now? Perhaps most of all, why did he go over that waterfall? From then on, it all just kind of meanders along and the behavior of certain people, especially Callum and his parents (much too casual about what happened), just didn't keep me engaged very well. To me, the intended point of this story is to highlight how everything in one's life can hinge on one small decision, much like the ripple effect of a stone thrown in a pond but getting the reader there is something of a drag. Callum now has one more decision to make but this one might have even more significance; he may die. Readers may very well treat this book on two levels. Some will see it as a somewhat simple story about a rift in dimensions while others will look for a deeper meaning, more navel-gazing, if you will. I enjoyed Undercurrent but I'm not sure it really reaches that more significant plane. The plot is really rather thin and slow and I would expect a moderately intelligent teen to come to grips with his different reality sooner than Callum did. Perhaps the premise would have been better suited to a novella format so that the author would have had to step up the pace.
BooksWithBite More than 1 year ago
Dimensional stories are a new genre that I'm really loving. It a mix of moving action along with a mysterious force, pulling the reader into different worlds. I, for one, loved this story. Plot: What would you do if you plunged into water and woke up in a different world? First, I freak out and then I think what do to. The plot moved well gathering the reader for great world building and characters. On the surface, the reader see and feels the gaps in the world. It's a daring experience trying to put everything together at once. I let the story guide me, putting myself in the thoughts of Callum, I let everything seeped into my mind slowly they way he did. He was smart and after thinking things through bit by bit, he slowly began to understand what is happening. It does move slow in the beginning, but it does have a lot of information to divulge, so give the book time to unfold. Characters: There are some minor character that put the final piece of the puzzle and helped Callum. I felt like these guys (especially the end) was the comedy relief guys. No one understood their weird comments or actions. I knew to pay attention more to these guys cause they knew more than what they led on. Callum himself, did a big change in taking a role he didn't want to play and well played it perfectly. He did act strange at first but he got it. Callum questioned why he was so different in this world and what happen to change it. I always wondered myself what I would be like in another dimensional world. *shrugs* Dimensional: This is the main part of the story and yes I loved it. It played out well from beginning to end, giving the reader an impressive experience. For me, dimensional stories are hard to pull off since they can be confusing. Blackwell doesn't confuse the reader at all, instead giving the reader a steady and exciting story to read. Undercurrent is a dark, impressive story. With the perfect ingredients of action, mystery and dimensions, Blackwell excellent story telling moves the reader. With a vivid execution from start to finish, Undercurrent is an entertaining ride.
Amabe421 More than 1 year ago
* Actual rating is 3.5 stars. I love YA books told from a male POV. I really think there need to be more of them. Especially ones that the voice is so well done like this one was.I'm also really enjoying reading alternate reality/alternate universe books. This one was really great in that it was an alternate reality, but it was really focused on the one that Callum is in, and doesn't switch back and forth between them. I do tend to get a little confused trying to keep things straight so this was very refreshing for me. I also loved the mystery element of it all, even though I figured out what was happening pretty early. The main character is Callum, and I really liked getting to know the real him (at least the one that we are currently in the head of). I also thought it was neat to get to know the alternate him who is totally different from who he is in his original reality. He is totally confused though. He wakes up in the hospital and soon discovers that things are very, very wrong. He has no clue what is going on, and slowly needs to figure things out. I thought that he made some really stupid decisions, but he managed. I liked that because he seemed very realistic to me. He messes up, he's insecure about things, he's scared. It makes me believe it more. There's not really much more I can say about the story, but it was really great. There was a good mystery and thriller element to it, and even though it was alternate reality, it wasn't really focused on that except when it was important and necessary to the story. I also liked how it ended, and I hope that a sequel is made for it because I would love the story to continue. I thought that how we get Callum's memories from his other reality and then it goes into his current reality was done really well.It gives a well rounded story of how different Callum is in each one, and the reasons why he is. This was great!! * An advanced copy of this book was provided by the publisher in exchange for an honest review. I did not receive any compensation.