"So it was a rush job to get you out of town, was it?" he asked, leading her to his car before opening the door for her. He could only imagine what reasons the Thorntons might have to rush her out of town.
Other options:
no subject
"So it was a rush job to get you out of town, was it?" he asked, leading her to his car before opening the door for her. He could only imagine what reasons the Thorntons might have to rush her out of town.