"The Vengeance Flies at Morning" was the theme song to Battlecruiser Vengeance, a Klingon adventure serial of the 23rd century.

The song went:

The guns are hot, the hull is ringing,
The engines sing the sound of triumph;
And every one aboard awaits
A prize upon the high horizon.
Hand and weapon! Heart and power!
Cry it with the voice of Empire!
Victory and prize and plunder!
Vengeance flies at morning!

The residents of House Gensa sang "The Vengeance Flies at Morning" to Vrenn as he departed to become Thought Admiral Kethas epetai-Khemara's adopted son in the late 2220s. Although "Undefeated" was the House's song, Vrenn was a fan of Battlecruiser Vengeance. (TOS novel: The Final Reflection)