Sci-Fi Friday: Norma and Norman at the end of the World

Norma muttered under her breath as she picked up Norman’s socks from the bedroom floor. Again.

"Norma love, would you like a cup of tea?"
Yelled Norman from down the hallway.
"Ok love so long as we have Yorkshire left! Just the one sugar though we’re trying to conserve it remember.”
"Ok sweety."

She heard Norman humming as he made the brews in the kitchen. She snuck behind him and kissed his neck cheekily and felt his body stiffen.
She chuckled.
"Sorry love did I startle you."
Norman pointed without saying a word to the garden. Norma looked out of the kitchen window.
A creature was shambling up the path towards the house. It's face frozen in a rictus grin of a skull. Flesh was hanging off it, the thing was dragging it's left leg behind it.
Norma tutted.
"Not again. They're worse than the bloody squirrels. I'll sort it out."
She reached into the kitchen drawer and took out a round device about the size of a baseball. She bustled out of the house and into the garden.

Norman heard her chatting to it.
"Bugger off why don't you."
He heard the grenade hit the ground then counted to three…