Boston Blue's newest episode really affected Donnie Wahlberg's character, Danny, who got emotional about his relationship with son Sean. During the Friday, December 12, episode of the hit CBS series, Danny (Wahlberg) and Lena (Sonequa Martin-Green) were put on a case involving a young child who saw his father get murdered. Danny was visibly shaken up and continued to be driven by his personal connection to the incident.