SEFFNER — The bookends are clear in the life of Sinatra, a 5-year-old, brown-and-white, blue-eyed Husky. Beloved by his teenage owner and her parents, Sinatra disappeared after the girl died in a tragic gun accident. Then earlier this month, he wandered into a neighborhood where people tracked down his family and arranged for them to be reunited this Sunday. But Sinatra can’t explain what happened in between — an 18-month, 1,200 mile journey that took him from his home in Brooklyn to the streets of Seffner. Neither can his owners or the family who found him. “I didn’t believe it...