Lyric discussion by teenrockteam 

Cover art for Quarantine lyrics by Phantom Planet

He's put up emotional barriers because of repeated attacks on his heart.

He really can't open up to anyone, really.

And this all happens because of some little flea, convincing someone to conspire against him.

And now the speaker is behind glass, only able to watch, but he put himself there, because he'd rather be alone than risk being hurt like before.

That's really all I could come up with.