Ram Narain, a scientist has set up an underground laboratory and is experimenting to invent a fire satellite which he feels should prove to be deadly weapon for the enemy.
The half of the plan of the way leading to the laboratory falls in the hands of John a spy of a neighbouring country whereas the other half is in the safe custody of Johny the only son of Ram Narain.
Bhupat Singh is also a spy from another neighbouring country. Since the target of both John & Bhupat Singh is same i.e. to sell the scientific formula of the fire satellite to their own countries they join hands to find it out. They could not succeed however, till they grab the second part of the plan for the way teaching to laboratory.
In order to do that they go all out to snatch if from Johny but Johny proves to be a far tougher match for them and manages to fail all their wicked plans.
Johny falls in love with Chandra the only daughter of police officer Bhim Singh. Somehow Johny and Chandra fall in the clutches of Bhupat Singh and John. They are both most inhumanly tortured and their lives can be spared only if they hand over the 2nd part of the plan showing the way to the laboratory.
Parting with it means treachery to the country otherwise it means their death. What do they choose? To sacrifice their lives, their country or to save both. Answer to this riddle can be found in the film, "RETURN of JOHNY".
(From the official press booklet)