Perhaps to send her to decontamination? Just a guess! Only rode a Greyhound once in my life. Wasn't exactly impressed with the service, employees, or the clientele. Pretty low rent. If I can't take the train or drive, I really don't need the trip. Never go far enough to fly.
Now, wait a minute there; don't go slandering Greyhound.
I rode a Greyhound bus one time, when I was a sophomore in college, from northern North Dakota down to Omaha; it stopped at exotic places such as Sioux Falls and Sioux City, and took a whole day.
Other than that the cuisine in the depots was overpriced, I had a good time, and the bus was immaculately clean despite the nature of most of the riders on it.