Paap Punya is Manglu s story. Manglu is a worker in a tea estate who is dedicated to his master. He hands over his son to his master when his wife delivers a dead child. Manglu brings up a deserted child as his own. Manglu s own son Rakesh grows up to be a spoilt brat while David his foster son grows up to be a good boy. Rakesh is jealous of David. Their enmity intensifies when David falls in love with Rakesh s fianc e and their real identities are revealed. Manglu murders Rakesh trying to save David and is jailed.