Sam tells Reddington that he wants Lizzy to know "the truth" before he dies. Reddington objects, stating that she must never know. He then kills Sam to end his suffering, and also to keep "the truth" hidden. ... Red comforts Elizabeth as she mourns her father.

What happened to Sam in blacklist?

“General Ludd”

Red goes to pay his respects, but smothers Sam to death when Sam tries to call Lizzie and tell her a secret about her biological father.

Who is Elizabeth Keen's real father?

Also, the real Raymond Reddington was Liz's father, whom she shot and killed as a child, spurring Katarina to send her to live with her adoptive father. Because no one was aware of Reddington's death, Katarina created a new “Red” (Spader) to watch over Liz.