Travis Bickle is an ex-Marine and Vietnam War veteran living in New York City. As he suffers from insomnia, he spends his time working as a cabbie at night, watching porn movies at seedy cinemas during the day, or thinking about how the world, New York in particular, has deteriorated into a cesspool. He's a loner who has strong opinions about what is right and wrong with mankind. For Travis, the one bright spot in New York humanity is Betsy, a worker on the presidential nomination campaign of Senator Charles Palatine. Travis becomes obsessed with Betsy. After an incident with Betsy, Travis believes he has to do whatever he needs to to make the world a better place in his opinion. One of his priorities is to be the savior for Iris, a twelve year old runaway and prostitute who he believes wants out of the profession and under the thumb of her pimp and lover Matthew.