Counter Clockwise, by Jason Cockcroft (Harper Collins, 2009, middle grade, 202 pages)
Nathan's mother was hit by a bus and killed. Now he and his father live a somewhat nervous life in an old apartment complex that's been condemned....existing, rather than truly living. But a chance encounter with a time-travelling beefeater just after Nathan's parentally-enforced evening physics class, and his father's disappearance through a father-shaped hole in the bathroom wall change things. Just a tad.
"[Nathan] took a step toward the hole and looked down at the ground far below, half expecting to catch the figure of his father falling in slow motion through the air, toward the parked car and burning Dumpster.
But there was no figure, and no man falling. There was nothing but the hole." (page 37)
It turns out that the mysterious beefeater has come forward in time specifically to find Nathan, so as to save the fabric of time from being destroyed by Nathan's father. Because his father has travelled back in time, to save his mother from the bus....and so Nathan follows, watching his own tragedy unfold....time after time.
I just noticed that the jacket flap promises "a startlingly original narrative structure." I'm not at all sure why anyone might think so. Maybe if you've never read a book about anyone trying to alter their own past, and changing their present in consequence, resulting in multiple narratives of the same time period, it would seem original....But I will grant that this is a rather nice example of such a book. There's a lot of emotional intensity to the story, re-enforced by the sympathetic secondary characters. And it's a rather gripping story too, what with its emotionally fraught central premise--in order to save the world, Nathan has to make sure his mother dies. I was eager to see how it all played out, and was satisfied at the end.
My one quibble is that the whole business of time travel is left somewhat murky. The beefeater does turn out to have a familial connection to Nathan, but if there was any coherent explanation about how he got to Nathan's time, I didn't pick up on it. Ditto Nathan's father's excursion through the bathroom wall--just one of those mysteries (although I have been known to miss things when I read, and I have a nagging suspicion that I read this one too fast. But it was because I was enjoying it).
A good one to offer a sixth or seventh grade kid (perhaps boy kid in particular) as a nice alternative to Fantasy-type fantasy, and a pleasantly diverting read, not without emotional punch, for the fan of time travel stories of any age (although it really isn't "startlingly original").
Here are other takes on this one from Literate Lives, Everything Distills into Reading, and Bibliophile Support Group.