Captain Alverez is the captain commanding the Spanish forces that are stationed at Manila at a certain fort that is essential to the Americans, who are invading the city. The captain is a dissolute sort of man, and in spite of the fact that his wife is pretty, he prefers the company of the other officers and spends all his time in gambling. One day the Senora gets sick and calls the American army surgeon, who is in camp nearby. As yet there are no actual hostilities between the armies. The doctor comes and a mutual interest arises between the two. Then comes the actual battle, and the captain, fearful that his wife is going to give away some secret to the enemy, locks her up in a barn. There she finds a dead soldier and dresses up in his uniform. In the meanwhile the battle has been raging and there is not much to choose between the two armies. Lieut. Jones, although with the medical corps, is fighting with the troops, and they are in great danger from the battery that is commanded by Alverez. So the Senora gets a barrel of powder, and making a hole in it, rolls it toward the battery. Then she lights the trail that the powder makes, and the whole battery and her husband as well are blown to kingdom come.
—Moving Picture World synopsis