The Children of Broadaxe Wood

Putrid streams that flow too slowly through a local wood, leaving puddles and pools of a hostile environment in its wake.
Where children used to play is becoming desolate and lifeless. Even the trees are showing signs of ill health.
But three children are determined to find out what ails Broadaxe Wood. Harry, Eric and Sam don't know how to tackle the problem, but they find an unusual ally in the form of a talking tree!