Jon Agee is a brilliant picture book creator — who has never won a Caldecott. In this year of breathtaking contenders, it might seem a stretch to suggest that his The Wall in the Middle of the Book could put him over the top (that's a little joke for those of you who already know this clever and surprise-twisty title). But hear me out. For ingenious use of the picture book form and structure, communication through body language and facial expression alone, comic pacing, and humorous unreliability of the narration, I don't think any other 2018 title comes close. (In these ways, it's this year's Sam & Dave Dig a Hole, a 2015 Caldecott Honor Book.)

This is a book whose strengths reveal themselves with every page-turn and needs careful attention from start to finish, as the book starts before the title page and important events occur in quick succession. You need to be paying attention to note that there's a brick missing from the wall that requires our clueless small-knight protagonist/narrator to climb a ladder to make repairs. And once he's up on that ladder, things happen quickly on both sides of the wall. We buy into his claims about which side of the wall is "safe" only for a few page-turns (until, that is, the tiny mouse frightens away the supposedly-terrifying rhino, tiger, and gorilla). And then readers need to reexamine their assumptions as they watch the floodwaters, which contain various voracious sea creatures, rise on the left side of the book and as the ogre enters, stage right, to prepare to step in when needed.

So. I said above that viewers need to pay careful attention in order to follow every unexpected development in the action. But — they also don't. The basic story arc is related through the interplay of size, shape, color, and the amount of white space. The book is exquisitely balanced as the proportion of white space shifts from left-side page to right-side page. And as the pages turn, viewers can't help but see the left side of the book/wall filling up with water/color/mass. The sense of growing menace is unmistakable; the build-up to that huge green fish is masterful.

Agee's use of shapes here is so effective. He uses shape to introduce crucial elements (with the ladder entering as a horizontal rectangle before being propped up against the wall to form a triangle; the crocodile, rhino, and tiger enter as a horizontal shapes as well). He uses shape to create symmetry (for example, on the "And that's a good thing" spread where the small knight is leaning his ladder on the wall, forming a triangle, while on the right side the tiger leans up against the wall, also forming a triangle) and then disrupt it (as on a subsequent spread the triangle on the right side collapses). He uses it to tease the viewer by suggesting false equivalence (as on the spread with the brilliant mirror images of the crocodile and the ogre). Finally, he uses it to definitively separate left side from right, with the horizontal lines of the waves and the striations on the massive green fish taking over on the left and the contrasting vertical lines of the tall ogre taking over on the right.

Color, too, is used with care and thought: the palette on the left, with its cool blues and greens, is a clear contrast with the palette on the right, with its warmer oranges and browns.

The text placement neatly reinforces the left-side/right-side division. The text is on left-hand pages, as long as our knight is still on his side of the wall; then there is a transitional wordless spread as the ogre plucks him from the now-very-deep water; then the text appears on right-hand pages after the knight arrives on the right side of the wall.

I haven't even mentioned the humor, and its perfect attunement to its audience. Even leaving aside how funny the small knight's unreliable narration is: note Agee's comic use of eyes. Check the duck espying the crocodile. Check the rhino noticing the mouse. And the funny "smaller fish being eaten by ever-larger fish" is certainly not a new trope, but it feels fresh here, and I think that's down to Just How Enormous that green fish is.

Who knew there was so much to this seemingly simple picture book?!? Well, in a general sense, the real Caldecott committee, that's who. Of course I have no idea if they are looking at this title, specifically. But any book they do consider, they pore over and read and re-read and look at again and again. And giving Agee's book repeated and close attention — one could almost say doing a deep dive ;) — yields huge rewards.