On August 28, 2005, Sheriff's Detective LaSalle responds to the scene of a fatally-wounded man, Phil Hart, who dies after giving a description of his killer, which included a shapeless blue tattoo.
In the present, the team investigates a murder at a diner; among the dead is a Marine officer. Percy and LaSalle also find a witness, Fray, who provides a familiar description of a shapeless blue tattoo on the killer's neck.
LaSalle realizes the connection to the ten-year-old case, and eventually they find that the same shotgun was the murder weapon and there was also the same trace evidence.
In various flashbacks, LaSalle continues to investigate the murder, eventually meeting Pride, who was hunting for an armed robber, who is the same man. To LaSalle's frustration, they hit a dead end and are unable to investigate further. Hart's widow gives birth.
In the present, the team realizes that the stolen Navy money was misplaced, and is now in the possession of Phil Hart's widow, and the armed robber, Taggat, wants it back. They go to the widow's home and are able to rescue them from Taggat, who is holding them hostage. LaSalle fatally shoots Taggat, finally closing that chapter in his life.
The team celebrates Thanksgiving at Pride's bar.