Once Lucas and Amy got into the car, Amy was silent as she tried to figure out what Lucas wanted to say to her and why he was going through that much trouble for her sake.
Although she had initially planned to go directly to the police station so they would accompany back home in case Malone was still there, but now that Lucas was going with her, her plan had changed.
She didn't want Lucas finding out about her trouble with Malone.
Lucas on the other hand didn't say anything immediately and just drove in silence. He wanted to arouse her curiosity enough for her to ask him to speak.
From his experience as a medical doctor, he knew very well how much people hated the suspense that grating silence brought.
Impressively, Amy was able to hold out for fifteen minutes before she finally gave in to her curiosity, "I thought you said you had something to say. Are you going to speak or not?" She asked, making his lips twitch in amusement.