Elmo's embarrassed by his eccentric mother, who's declared war on new next-door neighbour Mr Bamber over his plans to turn the local woods into a housing development.

But then Elmo makes friends with the Bambers' new adopted child, Kuba, who claims to be an undercover angel and insists that Elmo tries to stop Mr Bamber's plans too.

Together, they begin to put together a petition, but the cunning Mr Bamber has secretly planned to start his demolition work early.

In the final showdown, Elmo and Kuba stand in front of the bulldozers and when that doesn't work, Kuba proves that she really is an undercover angel and raises the living dead, scaring Bamber and his demolition men away and saving the woods.