Their only interactions were on opposite sides of the screen door — contemptuous staring matches that would have been much uglier had a barrier not separated them.

Inside the house was Casey, a tabby cat who had been his owner’s only feline until Sweetie arrived on the scene. Sweetie was on the outside, where she had been since her earliest days of life, when her mother dropped her and three littermates in Gordon Dyker’s carport in 1997.

Already caring for Casey and a dog, Dyker resisted welcoming four baby kittens into his Decatur home. But as the abandoned kitties perished one-by-one, Dyker felt obligated to save the one he could, a creature that could fit into the palm of his hand. He fed the infant food and water from the tip of his finger, and soon knew it would be part of his family, although Casey made it abundantly clear that his new step-sister could not live in the house.

“The two of them would go nose-to-nose, and the male cat, the tabby, really didn’t care for the competition,” Dyker says.

Sweetie gladly settled into the routine of an outdoor cat, climbing a Dogwood tree to get atop Dyker’s roof, coming to the doorstep in the morning and after work to eat, staring at Casey through the screen door. After eight years, Dyker moved to a new home, where Sweetie maintained her wandering routine and Casey maintained his dominance in the house.

Then Casey died and had to be cremated, and despite their estrangement, Sweetie seemed to sense Casey’s absence, and what it meant to Dyker.

“Sweetie would come into the garage, that’s where she would stay at night, then she would be let out during the day,” Dyker says. “And the day after the tabby died, instead of running out the back door, she just automatically came inside.

“Sweetie ventured inside the house, sat down next to me, and allowed me to grieve — with her by my side,” he adds. “She went up the stairs and did her own little business with investigating the house. She had never been in the house.”

And she’s rarely left since, settling into her role as an indoor cat.

“There was a transition, but to have a completely outdoor, feral cat eventually come in and jump up on your lap and allow you to brush her and put a collar on her and act as if she had always been inside, I would have never believed it,” Dyker says.