As rents skyrocket and cities pretty themselves, graffiti artists are doing their best to keep the city landscape looking seedy. PNS associate editor A. Clay Thompson hangs out with Grease and Solid to explain the logic behind this nocturnal campaign to curb property values. Thompson lives in San Francisco and writes widely on cultures and movements from the margins of society.

I grab the fire escape ladder and hoist myself up-- only to see a police cruiser crawling my way. I press my face to the metal-grate stairs, hoping the cops can't see me. They move along, and I proceed upwards, to the peak of the four-story industrial compound.

At the summit, I join "Grease" and "Solid." They are graffiti writers, strapped with spray paint, and they are on a continuing mission -- a battle against San Francisco, the new San Francisco, a sanitized city purged of grimy homeless lowlifes and housing project problem children.

While San Francisco rents are skyrocketing and the city razes public housing and buffs unauthorized writing from the walls, the scribes are tagging everything in sight.

Graffiti is direct action against gentrification, part of a campaign not on any politician's agenda: to curb property values by keeping the city seedy.

The view from our perch is stunning, the feeling serene. The chaos of the city disappears at this height. Busses and cars crawl quietly along 16th Street, bearing anonymous passengers to anonymous destinations. The lights of the Bay Bridge pulse like a string of Christmas bulbs. A swath of fog cuts the blue-black sky in half.

"I feel like my whole life was just preparation to come here, to San Francisco, to the Mission District," says Solid, who moved from the Midwest a year ago. "I feel at home here, I wanna stay here forever."

I know how he feels. I also know that I've been living here for five years and don't know how much longer I can stay. Every year the rents in this city climb higher and higher -- up 37 percent this year says the Tenants' Union, the highest rate of rent increase in the country.

Friends give me different versions of the same story. Landlords doubling rent on slummy two bedroom flats from $750 to $1,500 overnight. People "couch touring" for months. Folks paying $350 a month to literally live in a closet. Apartments jammed to the rafters with working folks trying get by in high rent hell.

I feel like my position in the city is questionable. Writing is not a high-paid profession. And I may be evicted again. I'm getting used to it. For the third time this year I've got a slumlord telling me he's looking for a "more desirable (i.e.: wealthy) tenant."

At this point, I don't know if I wanna live here for the rest of my days. My friends-- artists, writers, activists, service-industry wage slaves -- are already fleeing the Bay.

The low-paid can't afford to live here. Creative souls can't find the time to be creative in a high rent habitat. "When you live here you spend all your time worrying about making rent," says Mike a musician friend who plans to leave.

Who will I hang out with when all my friends are gone?

Grease and I step out onto the two and a half foot ledge that runs along the top of the building, about four feet below the roof. Solid hops onto the roof, scanning the street for cops -- our lookout. Grease wants to paint a four by eight foot graffiti silver and black mini-mural on the top corner of the warehouse.

Grease and I move slowly along the sheet metal precipice. It is wet with fog, oily, creaky with age. We reach the spot, and Grease starts to paint. Silver spray blows in my face. I can taste it in my mouth.

Suddenly, my sneakers begin sliding ever so slightly toward the edge of the slippery walkway. All at once I am paralyzed -- can't move, can't pull back. I see my self plunging right off the ledge.

But I recover, and shuffle very slowly back to the ladder that goes up to the roof. My brush with death brings other unpleasant fates to mind. Can I survive this dog-eat-dog housing war, or will I slip, end up on the streets, down on my luck in this soon-to-be city of the rich? Will I have find a (yikes!) suit and tie job to stay?

Grease finishes his painting. We head back down the fire escape. "If we all get pushed out of this city I'll still come back and write graffiti," says Grease later, "Just for retaliation. Just to leave a piece of me here."

I hope he writes my name on the wall, 'cause I don't know how long I'll last.