The Return of the Su

Qin Lang suddenly remembered, today was his release day, but also his father Qin Chuan's death anniversary. At this time, Qin Chuan should be lying in the hospital bed waiting for him, hoping to see him one last time!,A slow poison! And a particularly insidious, particularly troublesome kind of slow poison!,The doctors in this world can't cure this poison. Who is it, and what kind of grudge do they have against their father to inflict such a deadly blow。