Miketz. Awakening Sensitivity

In last week’s parsha, we read of the brothers’ hostility to Joseph, how they planned to murder him, and sold him to slavery in Egypt.
We never hear the brothers regret their actions; even after they witness their father’s deep grief.
But then Joseph has the brothers (falsely) accused of spying, and incarcerated for three days in an Egyptian jail. (Were they interrogated, even tortured, by the Egyptian secret-service?) At this point we are privy to a fascinating exchange:
“They said to one another, “Indeed, we are guilty on account of our brother, because we looked on at his anguish, yet paid no heed as he pleaded with us. That is why this distress has come upon us.” Then Reuben spoke up and said to them, “Did I not tell you, ‘Do no wrong to the boy’? But you paid no heed. Now comes the reckoning for his blood.” (43:21-22)