"Why do you keep looking back? Are you looking for someone?" Sabrina asked Robert.
They were at the train station waiting for their ride on their way to the new place Luther offered to them.
Sabrina and the brothers easily agreed to what they offered to them because a new and better life was waiting for them there. However, for Robert, it was a decision he needed to think about thoroughly.
If he leaves now, it will mean that he won't be seeing anyone in Mila's group anymore. Ultimately, he would never see Mila again.
No matter how much he wanted to convince himself that he hated Mila for deceiving him, a little part of him still missed Mila.
Robert keeps looking back, wondering if Mila might come running to him and stop him from leaving. But, of course, Mila wasn't there.