Act fourth displayed the despairing Roderigo on the point of stabbing himself, because he has been told that Zara has deserted him. Just as the dagger is at his heart, a lovely song is sung under his window, informing him that Zara is true, but in danger, and he can save her, if he will. A key is thrown in, which unlocks the door, and in a spasm of rapture he tears off his chains, and rushes away to find and rescue his ladylove.