If there is one debt in life, one karz which is most essential to fulfill it is that of blood. The blood flowing in your veins is an unforgettable debt to your father, your mother. And when you see that very blood flowing out of the body of the most cherished person in your life, you are compelled to fulfill that "KHOON KA KARZ".
Savitri is an orthodox lady, who having lost her husband and child, has devoted her life to bringing up orphaned children. One day, to her grief, she discovers that two of ashram's brightest boys, Arjun and Kiahsn, whom she had broght up with the utmost tender loving care, are actually two of the city's most hardened criminals. She wonders where her preachings have gone wrong, and prays to God to send his messenger to get these two out of the vortex of crime they are in. And as if in answer to her prayers, comes Karan.
All three Karan, Arjun and Kishan are victims of circumstances. Karan, because he finds his graduation degree of top honours treated with disdain and utter contempt. Arjun, because his dreams of becoming a scholar are shattered by his beloved Sagarika's corrupt father, a Commissioner of Police, and Kishan, because the school headmaster's taunts of his being a bastard child still echo in his ears. Arjun and Kishan have joined hands in crime and are under the patronage of none other than Champaklal, who along with his son Robin and Mantri Rasiklal has risen alarmingly in the world of crime. Robin holds a degree in crime obtained from America. Karan, who has seen through the heinous and nefarious activities of Champaklal, has vowed to destroy him. Fearing a strong enemy, Champaklal asks Arjun and Kishan to bump off Karan.
A badly injured Karan seeks shelter in Maa Savitri's ashram. On recovering, Karan pledges to Maa Savitri that he will reform Arjun and Kishan. Karan takes the help of Sagarika, Sheetal and glamorous model in love with Kishan, and Tara, the beautiful taxi driver whom he himself is in love with, and finally manages to make Arjun and Kishan see through Champaklal.
Sensing that his well built empire of crime is about to come crashing down like a house of cards, Champaklal orders Robin to kill Ma Savitri Devi whose preachings are working against him. A dying Savitir, true to their beliefs in life that she has always held dear, makes Karan, Arjun and Kishan vow not to tread the path of violence and not to avenge her death. But at the funeral pyre of their beloved mother, the three are disclosed a startling revelation!
What is this revelation? Is Karan the long lost son of Savitri? Do the three manage to break the chain of vow which has tied their hands against revenge? Does the law forgive them for their earlier committed crimes?
These are the questions, whose answers strike the viewers like bolts of lighting, in "KHOON KA KARZ".
[From the official press booklet]