Shining Armor is an average four year old colt, who loves his Mama and has heard about angels before. He's also never seen his Mama cry.
When he hears crying one night, he thinks it's an angel. He's not entirely wrong, since that's exactly what his Mama is to him. It's his mission to help her be happy again.
AU tag is used because it's a somewhat altered telling of my usual canon.
Very nice!
Oh dear god, that was the most adorable thing I've ever read in my entire life.
Adorable.
Minor nitpick: the dead in Heaven aren't angels.