Betrayal. It's a harsh word. The worst feeling in the world is finding out that someone you trusted has betrayed you.

Dean swallowed. Was this his tape? He could think of plenty of times he had betrayed Cas.

That's our next lesson. You're going to find out what betrayal does to a person.

This tape is about someone I trusted, someone I love. A dear friend. My own brother. Balthazar.

Dean let out a shaky breath. It wasn't him. But then, when would his name pop up?

You're dead at the time I'm recording this. I've arranged for this tape to come into your hands 24 hours before your 'll give you plenty of time to listen to all 13 tapes. And you'll already know what it is you did.

How did Cas arrange for the tapes to constantly go back and forward through time? He had to have another angel helping him. But who? They couldn't time travel without wings, could they?

So what did you do? You betrayed me. You sold me out. You gave my location to Sam and Dean, knowing they would stop me from doing what had to be done. I trusted you!

Balthazar did the right thing by turning you over. You had to be stopped. How can you still think you did the right thing?

And I killed you for it.

Don't think you can avoid your death either. My contact will erase your memory as soon as you deliver the tapes. You won't remember until a second before I kill you.

God, Cas.

I know now that opening purgatory was a stupid move.

Damn right.

But it doesn't change the fact that you betrayed my trust.

So thank you, Balthazar, for teaching me not to put my trust in anyone. Not even my own family.