In season four, after finally stopping "Jack", Sam retired from the VCTF, being replaced by a new forensic psychologist, Dr. Rachel Burke (Jamie Luner). Rachel was a former FBI instructor at Quantico who also had Sam Waters' skill of profiling. But unlike Sam, Rachel had a very brusque take-charge manner that alienated some of the team members. Rachel had her own life problems; being single and also dealing with Danny (Raphael Sbarge), her self-destructive younger brother who died from a drug overdose near the end of the season. Other subplots included Grace becoming pregnant with her second child, but her husband leaving her and having to face being a single mother, and George developing an drug addiction to painkiller pills after being injured in a minor car accident. Late in the season, the show established a new overarching (story arc) villain, a shadowy urban legend named Damian Kennasas. Gregory Itzin also had a recurring role as Joel Marks, an unstable FBI agent who stalked Rachel. As the series came to an end on an unresolved cliffhanger (with Rachel getting arrested after the unseen Damian framed her for Marks' murder by using the motive of wanting revenge against him for Danny's death), it appeared that the elite VCTF team might be shut down by the U.S. Congress for the high funds it took to operate.