The film opens on the evening of 24 April 1974, as a young conscript soldier (Daniel) kisses farewell to his girlfriend (Rosa) before boarding a train from Lisbon back to his Army base at Santarém. Both are fearful that he will be sent to fight in the Portuguese Colonial War. Late and depressed, Rosa then travels by tram to Antónia's flat to babysit for her daughter Amelia. On arriving back (late) at his base, Daniel is oblivious to the imminent coup. Captain Salgueiro Maia arrests the base commander at gunpoint and orders the soldiers to assemble on parade in the middle of the night; he asks them to come with him to Lisbon to overthrow the government. Maia's erudite but cynical and cautious colleague Major Gervasio refuses to take part, as does Lieutenant Lobão.