[1][2] Udham Singh Kamboj was born and brought up in a Sikh family in Punjab, British India.

Enraged over Jallianwala Bagh massacre that took place in Amritsar in April 1919 during the day of Baisakhi festival, Singh swears vengeance.

In order to achieve his vengeance, he travels to the United Kingdom, befriends some local Indians, as well as Irish nationalist, Irene Rose Palmer (Charleen Carswell).

He kills Michael O'Dwyer (Dave Anderson), the Lieutenant Governor of Punjab, who in 1919, who had authorised Dyer's use of force, during a program at Caxton Hall in London.

During his trial, he is offered the opportunity to state his case for acquittal but his remarks were deemed incendiary by the judge, who forbade the press from publishing them.