Horace Parker, a wealthy young egotist who agrees to finance a device for communicating with Mars provided that he is credited with its invention, remains home to study his plans rather than accompany Minnie, his fiancée, to a party. When he falls asleep, a figure appears, announcing itself as a messenger from Mars, whose mission is to convert the earth's most selfish man. Out in the streets the messenger shows him poverty and suffering, and he overhears Minnie's reproval of him at the party. On being taken to the home of a soldier whose wife he has refused to help, he awakens to find their house afire, rescues the woman, and invites other unfortunates to his own home, thus regaining the esteem of his fiancée.