How does Sweeney Todd end?

Todd did not kill the judge at that point, but was forced to let him go when the young man burst into the room and gave away in front of the judge that he was going to help Johanna escape. The judge leaves in a furious rage and Johanna is sent to a mental asylum as punishment for trying to deceive the judge. Sweeney Todd helps the young man concoct a plan to help her escape. Meanwhile, the little boy began to get suspiscious of Todd and tried to warn Bonham's character that Todd was an evil man. She then locked the little boy in the room with all of the dead bodies, knowing they would have to kill him. He sees what they are doing with the corpses and is justifiably horrified. He manages to escape through a sewer and Todd and Bonham try to find him but get distracted from the pursuit. The homeless woman that you see throughout the movie is caught in the barbershop and Todd cuts her throat and dumps her body downstairs like all the others. Sweeney Todd lured the judge back to his barbershop by having sent him a letter in advance telling him of the plan to rescue Johanna and tells him that the young man will be bringing her to his barbershop at midnight. The judge arrives and is convinced by Todd to get a shave while he is waiting. At that point he reveals his true identity and kills the judge. Unbeknownst to Sweeney, the young man had already brought Johanna into the room and hid her in his chest. She witnesses the murder and he sees her peeking out of the chest afterwards. He comes THIS close to killing her as well, since she's dressed like a boy and he doesn't recognize her as his daughter. He is distracted by Bonham screaming b/c the judge hadn't completely died and was grabbing at her while she was trying to dispatch his body. Todd lets Johanna go with a warning to "forget his face" Todd goes down to investigate and the bodies of the judge and the homeless woman are lying there. Bonham recognized the homeless woman first and is quickly trying to dispose of her body before Todd does as well, but is too late and Todd finally sees that the homeless woman is actually his wife. He then is furious at bonham for lying about his wife having died and then pushes her into the furnace. He is lying there holding his dead wife in his arms, when the little boy sneaks back up through the sewers and cuts Todd's throat. Todd dies dripping blood on the body of his wife.