He decided to take matters into his own hands and stole something from Glen's backyard.
But Glen appeared not to notice.
So Mal stole another thing.
And then another.
And then yet another.
And still another.
It turned out that that Glen hadn't actually liked or wanted that tractor tire, dilapidated barbecue pit, old clothes horse collection, Elk boneyard or black widow spider's nest.
Glen came to the fence to thank Mal.
And as Mal looked back over Glen's yard he couldn't even remember what about it had so pissed him off these past fifteen years.
And they became friends.
And one year they even took a vacation together.
Where Mal killed Glen for stealing his toothbrush.
After its theft had reminded him that the real reason he had been pissed off at Glen small that time was that Glen had stolen his wife.
He'd blocked it out after she had died the day she left him.
From a black widow spider bite.