The largest, strongest dog in the pack was miserable. He was born to be a leader, yet he wasn't. He was born to be special, yet he wasn't. He was called "Grumpy" by the humans. And while he was grumpy and sad, he had every right to be. This was not the life he was meant to have!

When Sean, Molly, and Eliza returned to their home, the mass of twenty-five giant Shiloh Shepherds frightened Eliza. She wanted her puppies!  Still, she could see the great sadness in the massive dog's eyes as he crawled submissively into her room. Her father explained that Grumpy expected to be pack leader, but none of the dogs will accept him.

She objected to his name at once, and once Sean discovered how smart and gentle the dog was with Molly, he suggested they rename him Sentry. When Eliza learned a sentry watches and protects, she agreed with the name change. Sean explained to Sentry that he was to protect Eliza at all times. The change in Sentry was remarkable. He now had the most important job in the world: protecting Eliza.