May 13, 1917; three little shepherd children, Lucia, Jacinta, and Francisco see a Beautiful Lady who claims to come from heaven. She tells them a mystery about later history of the world and calls for prayer and penance. Although the children are persecuted and mocked, they come to the meeting place every 13th of each month and the popularity of the miracle spreads. The movie does not only concentrate on the history of the children but it also accurately presents the Portuguese reality of the early 20th century. The country experiences the cruelty of WW I, atheist government and dangers for the Church. There are however, people who believe in God and listen to the message that the Virgin Mary conveys through Lucia.