Author's note: Just a warning, it gets a little confusing towards the end of the song because there is one line where there normally would be singing that is replaced by the characters actions instead. You'll see it. It's marked with an asterisk.
The scenario here is pretty much the same as it is in the musical, with Daroga simply following Erik down to his lair, gondola and all. No romance (unless you want there to be) and no hypnotism needed.
Again, I own nothing.
Chapter 2: The Phantom of the Opera
(Daroga)
Beneath the opera house,
I know he's there
I'm haunted by his face,
And the past we share
And now I realize
His dark charade
The Phantom of the Opera is just
His masquerade
(Erik)
Hello again, my friend
We meet once more
Our destinies collide
Like years before
And since you know the truth,
Don't be afraid
The Phantom of the Opera's indeed
My masquerade
(Daroga)
The genius you possess
Can't be denied
But underneath your mask
(Erik)
A freak does hide
(Both)
A creature of the dark,
That fate betrayed
The Phantom of the Opera is now
Your/my masquerade
(Voices)
He's here, the Phantom of the Opera
Beware, the Phantom of the Opera
(Erik)
In all your memories,
You've always known
That man and mystery
(Daroga)
Through you, they've shown
(Both)
And in this underworld,
Where music's made
The Phantom of the Opera became
Your/my masquerade
(Erik hands Daroga sheet music)
(Erik)
(Speaking) Sing it for me, Daroga. Sing it.
*(Daroga gives Erik a confused look, and Erik impatiently urges him on)
(Daroga)
(Quietly) He's there, the Phantom of the Opera
He's there, the Phantom of the Opera
Beware, the Phantom of the Opera
(Erik)
(Speaking) No! SING it, Daroga!
(Daroga)
(Louder) He's here, the Phantom of the Opera
AAAAAAAAAAAHHHHHHHHH!
AAAAAAAAAAAAAHHHHHHH!
AAAAAAAAAAAAHHHHHHHH!
(Erik)
(Speaking) SING IT FOR ME!
(Daroga)
(Loudest) AAAAAAAAAAAHHHHHHHHHH!
Did Daroga succeed in hitting that note at the end? Or did he crack? That's up to you. I think he did succeed, but you can imagine whatever you want.