This first book in a projected series is filled with potential and boasts an intriguing premise. There's just something about underground caverns and civilizations that is almost automatically appealing, and this is a particularly rich and nasty one, with cultish overtones and hints of an ancient history. And the authors have a knack for multi-sensory description that gives this tale an unusual grittiness as the characters, and thus readers, not only see the wonders and terrors of this underground world, but also smell them and feel the filth and desolation in a way that lets you know why they're often referred to as the bowels of the earth

But it also has some rookie mistakes from the first-time authors, and suffers from the lax editorial hand that has become all too common in modern children's fantasy. Clocking in at over 450 pages, the story meanders and drifts for the first third, often getting mired in exposition that will have English teachers everywhere yelling, "Show, don't tell!" It doesn't really pick up until nearly 200 pages in, which will cause it to lose all but the most avid young readers. Those who do hang in will be treated to an exciting and suspenseful adventure, though one in which readers won't feel that they've really gotten to know any of the characters well. But there's enough good stuff here to give readers high hopes for the sequel.

From the Book:
They found themselves in a huge space, almost as wide as a highway, which curved off into the distance on their left and right. And looking across to the opposite side, they saw the road was lit by a row of tall street lamps.

But what stood beyond these lights, on the far side of the cavern, was what really took their breath away. Stretching as far as they could see, in both directions, were houses.