The new Call of Duty: Black Ops II trailer that reveals the Zombies cooperative multiplayer mode — dubbed a game within a game — comes with an ear-splitting new song. The song is “Carry On” from the band Avenged Sevenfold. It should put you in the mood to start shooting zombies like crazy. Activision Blizzard and its Treyarch game studio released a new trailer for the Zombies mode, which is the first full revelation of its gameplay.

The song’s lyrics contain plenty of mysteries. What does it mean to “fly past the edge of the sea” or “battle the will of those who conspire” or that “we’ve got to move higher?” Zombies fans are plentiful and are a key part of the success of Black Ops, which is one of the fastest-selling video games of all time and generated more than $1 billion in retail sales. And the fans are hungry for any tidbits of information that give a hint to the background story behind Zombies.

Here are the lyrics to the song:

Some people live that selfish desire,
Some choose to shout when they speak and they’ll be the start,
Caught in the flame of those deep in fire,
Seeking out those with a voice,
One for tomorrow.

They say we’ve lost our minds, we’ve just gained control,
Search endlessly, fight till we’re free,
Fly past the edge of the sea,
No bend in me, no mockery,
Somehow we still carry on.

(Fear, fear, fear, fear, fear, fear)
Silence your fear, we’ve got to move higher,
High like the stars in the sky,
Guiding us all,
Battle the will of those who consṗire,
Take back the passion to live, vanish the sorrow.

Destroys their perfect crime, watch the power fold,
Search endlessly, fight till we’re free,
Fly past the edge of the sea,
No bend in me, no mockery,
Somehow we still carry on.

Search endlessly, fight till we’re free,
Fly past the edge of the sea,
No bend in me, no mockery,
Somehow we still carry on,
Carry on.