Under the orders of newly elected Prime Minister Margaret Thatcher in 1979, the English decide to crack down on the IRA. When two Irish Catholics, Gerard Quigley (Aiden Gillen) and Frank Higgins (David O'Hara), are involved in an attack against a British military unit, they are arrested and sentenced to long jail terms, joining other members of the IRA in prison.

Under the leadership of Bobby Sands, who is elected to Parliament while he is in jail, the Irish prisoners begin a protest. They want to be considered as political prisoners and treated as such under human rights treaties. Eventually, the men go on a hunger strike to make their point.

Some Mother's Son is a riveting political drama about the importance of conscience and following the imperatives of the heart. The real protagonists are Kathleen Quigley (Helen Mirren) and Annie Higgins (Fionnula Flanagan), the mothers of Gerard and Frank. Director Terry George probes the friendship between these two women who initially have different attitudes toward involvement in Irish politics.

When the time comes to take a stand to save the lives of their sons who are starving to death, one of the women surprises everyone with her decision. Some Mother's Son hurrahs the courage it takes to follow the path of the heart.