When boarding was finally announced, the agent came back, a slight smile of satisfaction on his face. “Ma’am,” he said firmly, addressing the passenger, “service animals are protected by federal law. He is allowed on board. However, since you mentioned allergies, I can offer you a seat farther away from the passenger and her dog.”

The woman’s arrogance melted away. “I shouldn’t be the one inconvenienced!” she exclaimed. “This dog is—”

Before she could finish, a deep voice interrupted.

“Excuse me.”