Details: "Halloween Story Contest"

Here are the details about the "Halloween story contest" assignment, as well as a (partial) sample that I wrote:

DIRECTIONS: Write the ending to author Bruce Coville’s story, “Back From the Grave.” Your assignment should be 200-250 words (following the contest rules) in length and typed. It is due Monday, October 15.

Here’s my (unfinished) ending:

Suddenly, a scream exploded in the Avery’s bedroom next door.

I flung off the covers and sprinted toward the sound of Avery’s frantic cries.

I threw open her bedroom door and charged in. She was standing at the window, and I could see Avery silhouetted by the light of the full moon.

“No!” she shrieked.  “Gramma, Run!”

Running to the window, I pushed Avery out of the way. I stared with horrified disbelief at what I saw.

Gramma, in her pink fleece nightgown and furry slippers, scrambled through the back yard. Something was following her.

 I stood there, paralyzed with horror, as the dark figure closed in on Gramma.

Avery sprang into action. Opening the window, she quickly climbed through and lowered herself the short distance to the ground.

“Avery, stop!” I yelled at her.

Ignoring me, Avery ran to Gramma’s tool shed, ducked inside and emerged seconds later carrying a long handled shovel.

Was she crazy? Avery can barely lift that shovel, I thought.