Lyric discussion by Raving Lunatic 

All the songs on the album "We Shall All Be Healed" are about John Darnielle's youth. Apparently he was pretty big into drugs.

I think that in the first stanza, the line "things that you've got coming will consume you" refers to the drugs he is about to acquire. Then the person "waiting out there in an alley with a chain" is either the police (waiting to jail him) or a drug dealer (whose drugs are a metaphorical chain on the user).

The "Dull pain" in the second stanza refers to the pain that you get any time your addicted to something and have to go without it for a while.

Later on, I think the narrator desperately needs to have his drugs, and so he drives (past Garden Grove) and as he gets closer to acquiring the drugs he gets excited (the pleasure index rises).

Diamonds are a metaphor for the drugs as well, I think, while "the ghosts that haunt your building" are the feelings of addiction that come from withdrawal from a substance he is addicted to.

I have no idea what the chorus means. Who or what are the Young Thousands?

I think you're right, generally speaking, but I don't think the chain is a metaphor. A heavy chain is a pretty effective improvised weapon of the sort a drug dealer might carry.

An error occured.