Destroyer's Invocation Message
In the Halo 2 soundtrack Destroyer's Invocation, (the first movement of the Mausoleum Suite on the Halo 2: Original Soundtrack, a mysterious voice chants. If this mumbling is reversed (listen), a voice is heard saying:
- ...I have walked among men and angels for three thousand years. Time has no end... no beginning... no purpose.
- I wander the earth, seeking forgiveness for my horrible crimes against God and man.
- I live to see death and destruction, evil... over the light, but the light cannot be extinguished.
- I live in a prison of my own demise.'
- I am lost...in time
The voice can be heard in the beginning cutscene of the level The Arbiter, the level Gravemind when John-117 rescues the Marines, and during the level The Great Journey when Thel 'Vadam battles Tartarus.
 Black Tower Message
In the Halo 3 soundtrack, during the first few minutes of the track Black Tower, there is yet another message that can be heard if one reverses the song. Here is a transcript:
- Eyes from Death's dream kingdom,
- Appear as sunlight on a broken column.
- There in Death's other kingdom walking alone,
- Trembling lips form prayers to broken stone.
This message appears to be a reference to T.S. Elliot's Poem, The Hollow Men. The first part of the transcript refers to lines 20-23.
- In death’s dream kingdom
- These do not appear:
- There, the eyes are
- Sunlight on a broken column
The second part refers to lines 47-49.
- Waking alone
- At the hour when we are
- Trembling with tenderness
- Lips that would kiss
- Form prayers to broken stone.
 Dread Intrusion Message
In the Halo 3 soundtrack, a reversed message can be heard in the tracks Gravemind, and Dread Intrusion. The entire message is currently unknown, however, several lines are intelligible. Oddly, the voice during these messages sounds different from Gravemind. It echoes considerably, rendering several lines unknown, it is much deeper in pitch, and multiple other voices can be heard. This could be a reference to multiple Graveminds from the past that speak as one because of inherited knowledge. The first two lines both have 7 syllables each, a possible 7 reference.
- Side by side, we march as one,
- Humans and Elites will die,
- The Earth will fall if we strike together,
- So forth shall all of life.
The exact person who is speaking is unknown. Just like the Destroyer's Invocation Message, there are many possibilities about who it could be. The likely candidates are the Gravemind and the Prophet of Truth, since only Elites and humans are mentioned.
 Data Pads
- Covering data
- Corruption contained
- Breach identified
- Welcome Child
- Protocol to maintain
- Lineage confirmed
- Rogue confirmed