One and Only
performed by Unknown

This version of the song refers to the accapella version (supposedly) sung by Derek's family in the movie [Step Brothers]. It is unknown who actually sang the song.

Old Bulgarian folk song

The team searches for Chris Manning, a family court judge with a soft side who went missing after meeting with a young boy caught between his mother and his abusive father. Suspicion initially turns to anyone Manning may have riled up due to his court rulings, but after his clerk is shot in what appears to be an attempt on Manning's life, the team learns that the secret behind Manning's disappearance is tied up with something that happened over twenty years earlier.