Nandu is an orphan. At a very young age, he knew and saw the hard realities of life and had but no choice to learn the guerrilla antics of survival in the concrete jungle called Mumbai. Entering the world of crime was the only path available to him and he had done it almost relentlessly. He turned into an assassin… he had murdered his first victim at a tender age of 9.
Nandu found his family, his friendship all in one person, his aid Shekhar. Nandu grew up to be a cold-blooded assassin and Shekhar the getaway specialist. Together they bonded and had deep sense of understanding; they were each other's best comrades.
The opposition leader Anna Mhatre hires Nandu for a unique job. He wants Nandu to make an assassination attempt on him while he is addressing a rally for his election campaign, and Mhatre's motive is to create a sympathetic wave so as to tide over the elections into an overwhelming victory.
Nandu and Shekhar prepare for the job and on the day of the rally all seems to be going as planned. But just before Nandu is able to lock his target, another shot is fired leading to the cold blooded murder of Anna Mhatre. Nandu is shocked but knows he must make a quick getaway unaware that yet another horror faces him. Shekhar's car is blown away by a truck in an accident and the police are now surrounding and closing into Nandu. Nandu with his guerrilla expertise of over the years manages to make an escape by leaping onto a running train.
On the train Nandu meets Puran, a simple boy from Punjab who is returning back to his homeland after a long gap of 18 years. Puran in his excitement of returning to his family after so long narrates his side of the story to Nandu, and talks about how his family that still pines for him, he shows him his grandfather's eagerness to have his grandson back in the form of a newspaper ad and his watch that he has still treasured, he narrates to him about his closely knit family consisting of 3 aunts, 2 uncles and their kids. He emotionally speaks of his younger sister now ready to enter wed lock and Preet, his father's best friend's daughter who has been living with them since childhood, whom Puran deeply loves, and for Preet too Puran is the love of her life.
The police however have not given up their trail on Nandu and when the train halts at the next station, Nandu discovers this. An officer spots Nandu and aims a shot at him which accidentally hits Puran , who dies on the spot, his eyes imploringly staring at Nandu...... by the time the police converge into the compartment they find Nandu missing.
The beautiful quaint house is set in the midst of greenery and the pure air fills the heart of one and all. Puran's grandfather, Preet and his entire family are eagerly awaiting his arrival.
Nandu has decided to come to Puran's house to break the news of Puran's tragedy, handover his treasured belongings and his second reason is to find shelter for some time, away from the police who are still thick on their hunt for him.
Nandu arrives and is mistaken for Puran. Emotions take over everyone as each one comes forward to meet him and Nandu for the first time tastes the sweet pangs of love and care from the family. Nandu sees the hidden pain in this family and yet the strength with which Puran's grandfather has held the family till date. His decides to remain there as Puran.
Thus Nandu now Puran starts living within the family as its own member. He experiences, love, care, pain and goes through a lot many emotions as he is showered by so much love from all within the family. He bonds the most with the grandfather and the eldest bhua. Gradually he also starts falling in love with Preet. Nandu has forgotten his past and becomes Puran, helping the family in all its needs as if the family is his very own.
The case of Anna Mhatre's assassin is heating up and a special officer from the CBI, Nandkumar Rane.... Popularly known as Insp. Rane, is given the responsibility of this case. Insp. Rane has his own unique way of functioning and his investigation leads him to Punjab to Puran's house where he meets Nandu. Insp. Rane is now a threat to Nandu's existence.
Thus begins a game of one up-man ship between Insp. Rane and Nandu. Nandu also realizes that he is being driven to a situation where the only option in front of him is to find out the truth behind Anna Mhatre's murder.
Will Nandu be able to come out of the crisis? Will Puran's family find out the truth? Who is the real killer of Anna Mhatre?
Ek- The Power Of One is a journey that Nandu undertakes and in the process learns the true meaning of life.