S1, E13: Jack is distraught and defensive when Chet Collins (recurring guest star Charles S. Dutton), whose son has been missing for 6 years, decides to search for him on his own because he thinks Jack has given up hope of finding him. Feeling guilty over his failure to recover Collins' son, who was 2 years old when he disappeared, Jack kept the case active despite fearing the worst. However, after Collins comes in with another clue, Malone becomes angry and tells him that the case will never be solved. The team gets involved when Malone fears that Collins will do something desperate to finally get his child back.