Sweeney Todd is originally a Stephen Sondheim musical which Tim Burton used as a base for his 2007 film.
Benjamin Barker has been exiled and imprisoned for 15 years in Australia. He manages to escape and is rescued from the sea by Anthony Hope, a sailor on the Bountiful from Plymouth. He returns to London, bunking with Anthony. It's at this point the story that we see begins.
When the two arrive in London, Barker explains to Anthony his history, detailing how he was happy and in love with his wife and child (Lucy Barker and Johanna), but Judge Turpin also had desires on Lucy. In order to get her, he invented charges and had Barker arrested and exiled.
Under the name of Sweeney Todd, Barker returns to his old barbershop above Mrs. Lovett's pie shop, where he learns from her that Judge Turpin, soon after having him transported, lured Lucy Barker to a masked ball at his mansion and raped her. Lucy poisoned herself soon after the attack, and the Judge kidnapped Johanna and adopted her as his own. Sweeney vows vengeance upon both Judge Turpin and his evil assistant Beadle Bamford, who together masterminded his exile to Australia and destroyed his family.
Sweeney shows up a traveling barber, the conceited Italian Signor Adolfo Pirelli, who turns out to be not an Italian but a London boy who once served as Benjamin Barker's apprentice. He recognizes Sweeney's silver-handled cut-throat razors and threatens to reveal Sweeney's real identity, demanding half of his earnings. Sweeney slits the Signor's throat and hides the body in his trunk. Upon finding the body, Mrs. Lovett sees an opportunity to make her poor business shine; she wants to fill her pies with human flesh.
Sweeney discovers that Johanna has been kept under virtual house arrest under Judge Turpin as his ward, and has grown up into a beautiful teenage girl. In the years that she has been living with the Judge, Judge Turpin has come to desire her as more than just a daughter.
Johanna is one day seen by Anthony, who falls desperately in love, and swears to save her from her tyrannical guardian and marry her. He sings to her but is attacked by Judge Turpin and his Beadle who warn him never to come back to see Johanna.
In the meantime, Mrs. Lovett's pies have become famous in London. And next to all this she dreams about becoming respected and live a life by the sea with Sweeney as husband, and Pirelli's former assistant Toby, that she has taken to herself as an adoptive son.
But Sweeney's only thinking of revenge, and this could cost him painfully much...