It's the Hogwarts Ball, and there is a karaoke session. A very drunken Professor Snape slams down his wine glass, barges past the students and takes to the stage. His eyes fixing on one particular student...

At first I was afraid - I was petrified
Kept thinking how I could teach someone I can't abide
But I spent so many nights thinking how your father did me wrong
I grew strong
I learned how to take you on
and just like back in Grimmauld Place
When I walked in to find Black there with that same old arrogant face
I wish I'd exchanged my stupid job
Or forgotten Occlumency
If I had known for just one second Dumbledore would bother me

Go on now go!
Get out the door
Just turn around now
'cause you're not welcome, Gryffindor
Five years on Potter, you'rerunning out of lies
He thought I'd trust you
He thought he'd create allies

Oh no, not I
I am a spy
as long as I know how to sneak I know I'll stay alive
I've got all my life to live
Now I've House points to play with
And I'll survive

I will survive...

It took all the strength I had not to come apart
Kept trying hard to calm the madness of my grudging heart
And I spent oh so many nights just feeling sorry for myself
I used to cry
Now I hold my head up high
Now they see me
As somebody new
Scared now that snivelling little oddball's sneering back at you
And so you sent James Potter's son and expected there to be glee
But now he saving all his hatred for one and only, me!

Oh no, not I
I am a spy
as long as I know how to sneak I know I will stay alive
I've got all my life to live
Now I've House points to play with

And I'll survive

I will survive!