The song The Edge of Darkness is performed by Iron Maiden .
I've looked into the heart of darkness
Where the blood-red journey ends
When you've faced the heart of darkness
Even you soul begins to bend
For a week I have been waiting
Still I am only in saigon
The walls move in a little closer
I feel the jungle call me on
Every minute I get weaker
While in the jungle they grow strong
What I wanted was a mission
And for my sins they gave me one
They brought it up just like room service
'cause everyone gets what they want
And when that mission was all over
I'd never want another one
I know captain
That you've done this work before
We've got a problem
You can help us I am sure
The colonel's gone rogue
And his methods are unsound
You'll take a pbr up river track him down
There's a conflict in every human heart
And the temptation is to take it all to far
In this war things get so confused
But there are some things that cannot be excused
He's acting like God - an insane lunatic
Your mission - exterminate
With extreme prejudice
The route is dangerous
And your progress may be slow
Here's the file and it's all you need to know
Here I am the knife in my hand
And now I understand why the genius must die
Now I stand alone in the darkness
With his blood upon my hands
Where sat the warrior the poet
Now lie the fragments of a man
I've looked into the heart of darkness
Where the blood-red journey ends
When you've faced the heart of darkness
Even you soul begins to bend