Part One of the 'Epic Fail' anti-fantasy trilogy.
Strange immortals, each forever stuck at a suspiciously binary age - 8, 16, 32 or 64 - are exiled into an infinite forest from which there is no hope of escape. Four of them are summoned by the ancient Hidden One and tasked with an impossible quest: to go 'somewhere', to find 'something', and to do 'something' with it. This is all they know. The 'thing', whatever it is, could be anything, and it could be anywhere. I know, right? Failure is always an option!
I co-authored Entropic Quest with my son, who was age 8 when we started but who has (fortunately for him) grown older since.