Even with a fresh needle, it takes a couple of taps to penetrate the callused walls of the vein in Bob's right arm.

Some junkies rotate where they shoot up to prevent abscesses. But for the past seven years, Bob has injected his heroin through the same pin-cushioned quarter-inch of flesh, the crook of the elbow where nurses draw blood.

"I've got blood on my shirt," says 27-year-old Bob. "I'm always leaking."

Bob and his girlfriend, 18-year-old Leah, are two of the hundreds of homeless who spend their days in and around the streets of Cambridge. For Bob and Leah, those days involve stealing, selling, buying and shooting up. Bob's been shooting up since he was 18. He's a regular at the Youth on Fire drop-in center in Central Square and carries a list of methadone detox clinics in his pocket.

Leah says she kicked heroin three weeks before. But she helps Bob fence stolen goods and looks the other way while he scores.

This is the story of one Friday afternoon in their lives.


Daily hustle

When Bob and Leah (their names have been changed) woke up this morning at their "squat"
a rooftop elevator shaft in Allston-Brighton - they took Ecstasy. They stayed there for about an hour or so before hopping the 66 bus to Harvard Square.

"I woke up. I didn't have any money in my pocket, but I've got my girlfriend here who I love very much," says Bob. "I got my daily hustle here. I've got DVDs, box-set CDs. All brand-new. I've got my daily hustle, so I can start the day off with money. It's gonna be a good day."

Bob's days have unrolled with a numbing regularity since he was a teenager in Vermont: steal something, sell it and buy drugs. These days he boosts DVDs and CDs, then sells them or has Leah sell them in music stores from Central Square to Davis Square to Allston-Brighton.

"Every time he goes into a store [to steal], I have a heart attack," says Leah, a Billerica native who met Bob in Harvard Square four months ago.

"I'll be gone two minutes," Bob says with an impish grin, "and come back with 20 DVDs. Everybody wants DVDs."

Odds are, Bob has something you want.

Today his black "boost bag" holds a boxed set of 12 Grateful Dead CDs and a DVD of "Kill Bill." He says he stole them the night before from a Harvard Square store.

Bob isn't just a good thief. He's also a natural-born salesman.

"I can sell anything to anybody," he says. "It's how you talk to 'em. I don't care if he's got it already, I can talk him into buying it again. I've done it."

On the street, Bob gets about $10 for each DVD. A store will give them only between $4 and $7. The day before, he had sold a similar Grateful Dead boxed set for $50 in Davis Square. The couple keep a bolt cutter in their backpack and an eye open for nice bicycles. A $1,700 bike can bring up to $400, but you can only sell them every so often without raising suspicions, Bob said.

Stealing enough to support a daily heroin habit of $100-$150 wears on Bob.

"I've been doing it every day," he says. "But you feel it inside that if you keep doing it, you're gonna get caught."

Bob says his criminal record is mostly drug charges, with four or five counts of possessing stolen property.

"If I get arrested, I'll be gone for a while," he says.


"Keno tickets"

As the Ecstasy high wears off, Bob knows dope sickness won't be far behind. So he calls his dealer.

Bob always uses the same guy, a connection in Allston-Brighton who delivers relatively pure heroin. The purity of street heroin has increased from about 3 percent in the 1970s to around 50 percent today. It can approach 80 percent purity.

Residents of East Cambridge were alarmed to learn this summer that heroin was being sold near the Cambridgeside Galleria for a Boston-area low: $3 a bag.

Bob confirms the price - but says the cheap stuff is no bargain.

"They got $3 bags, $5 bags, $20 bags, $10 bags, $40 bags, $50 bags, $100 bags," says Bob. "I don't even go buy it unless I've got at least 50 bucks, 'cause it don't even touch me."

If Bob and Leah can sell a few CDs, there'll be enough money to buy a half-gram from his connection. They catch the 66 bus back to Allston-Brighton.

Bob waits down the street while Leah sells the CDs. She gets $15 for them. Combined with $35 from earlier sales in Harvard Square, that's enough for Bob to buy $50 worth of white powder heroin.

Things don't always go as planned with the dealer. The day before, Bob had requested "Keno tickets," code for heroin. The dealer showed up with cocaine instead. Bob adapted.

"He gave me an OC 20 for making a mistake," he says, referring to OxyContin tablets, a prized prescription painkiller.

Bob slammed the coke, which he said made him paranoid. Over the years, Bob has alternated between downers like heroin, which is chemically nearly identical to morphine, and uppers like coke or crystal methamphetamine. He said he once injected five syringes of Jack Daniel's.

"Half the high is the needle going in my arm," says Bob. "I could stick a needle in with nothing in it and I'd get high from it."

Bob takes the $15 from Leah and walks several blocks to meet his connection.


"Like someone beat me"

Every eight hours or so, Bob has to shoot up. Otherwise, he gets dope sick.

For him, that means flu-like symptoms: sweating, his skin goes white, his nose runs.

"It hurts like a bastard in the legs," Bob says. "I feel like someone beat me in the legs with a baseball bat."

When Bob returns from his buy, he motions toward a below-ground stairwell. The landing at the bottom is flooded with water to a depth of four inches. A partially swamped door reads "Caution - Electrical Room." A label from a Grateful Dead boxed-set floats in the stagnant water.

Bob stands four steps above the water, well below eye level for people passing on the street. He lays out his gear on his backpack and gets to work. His movements manage to be both easy and hurried at the same time.

He crumbles the half-gram of white powder into a tin cooker. He draws water from a vial into his needle and squirts it into the cooker, then uses the plunger end to mix the powder and water. He heats the mixture with a lighter, dissolving the heroin.

Holding the mixture with one hand, he wrestles the filter out of his cigarette with his teeth. He picks the needle back up and draws the mixture through the filter and into the syringe. He taps the needle to make air bubbles rise to the top, then squirts them out.

He aims at the well-used vein in the bend of his right arm. It takes a few taps to slide in. Down goes the plunger and the heroin heads to his heart. Soon after, the heroin leapfrogs the blood-brain barrier.

In movies about heroin use, this is when the user passes into euphoria. If seated, he invariably falls backward onto the carpet.

Not Bob.

He fills his needle again and slams the rest of the heroin. Then he gathers his gear and walks briskly away. He takes a different route back to where he'd left Leah.


"He wouldn't give up"

Bob and Leah first met in Harvard Square. Bob landed there on a Greyhound bus from Keene, N.H.

The daily round of stealing, selling, buying and shooting up might not seem to leave time for romance. But Bob's sales skills aren't limited to hustling DVDs. He persisted for a month in getting Leah to give him the time of day.

"He wouldn't give up, either," she says, a hint of a smile breaking a seemingly brusque demeanor.

For the past three months they've been inseparable.

"Everything we do, we do together," says Leah.

After shooting up in the stairwell, Bob is high. He's sweating a little. He wants a hamburger. He ducks into a McDonald's while Leah waits outside. He stands in line a while, then comes back outside to get a quarter from her. Tomato costs extra. And Bob loves tomato.

The couple most often eats McDonald's or a slice. They know when the various homeless outreach programs have meals. Mac and cheese at Youth on Fire, ham sandwiches at The Bridge Over Troubled Water van. Bob sometimes lifts junk food from drug stores, especially the peanut butter M&M candies Leah loves.

The couple boards the 66 again, back to Harvard Square. Bob gets a little sleepy during the ride, leaning into Leah's shoulder. She lets her pet rat, Pinkerton, out of her plastic carrying cage. Pinky is a shy, domesticated rat with white and brown markings. She cautiously ducks around Leah's shoulders, under Bob's hoodie and soon asks to get back in her newspaper-filled cage.


"I hated my life"

Bob started smoking pot and drinking at 14. He hung out with older kids and got into stealing, cutting school and experimenting with other drugs. He sniffed his first heroin at 17. At 18, an older user injected him for the first time.

"You start out small," says Bob, "and you do it four or five days in a row and that's it. You're stuck on it. You go to not do it again and its unbearable the way you feel. Next thing you know, your habit is way out of control and you don't even realize it."

Bob goes clean from time to time. He's detoxed at least five times. But with the drug screen gone, Bob says, depression's dull gray grip tightens again.

"All those old feelings start coming up," says Bob. "You get depressed and you want to make that pain go away."

Bob traces the pain back to when he was 5 and his little brother died. Bob believes his mom's boyfriend shook his brother to death.

"I was so depressed. I used to cut myself up. I hated my life," says Bob. "And like from kindergarten on, I was busting up books, acting up in class. I wanted my brother back. That really took a toll on me."


"I'm a survivor"

Bob and Leah exit the 66 bus and walk back to Cambridge Common. Bob has perked back up. They sit on the same stone bench they'd left three hours before. Bob takes out a list of phone numbers for methadone detox clinics. He starts dialing. He'd like to get into one starting the next morning, but finds he's too late for that.

"I was going to do that today, but it's looking more like Monday now," says Bob between calls. "I really want to stop doing this dope. I can't keep doing this. It just sucks. She really wants me to get off it. She hates me doing it."

Leah kicked heroin three weeks before. She's still on her father's health insurance and was able to go to a private doctor. That meant getting the Cadillac of withdrawal drugs, bupenorphine.

"It worked good for her," says Bob. "I took a couple of them and it worked OK. You don't feel the dope sickness. You don't feel the withdrawals when you come off [the bupenorphine]."

Leah says Bob and Pinky were by her side when she detoxed. She plans to stick with Bob through his.

With winter coming on, the couple needs a better place to stay. They talk of renting an apartment, something that might be possible if Leah keeps her new job in a department store and a potential demolition job works out for Bob.

"I'm a survivor. I'm street-smart," he says before dropping the bravado a notch. "I can't keep living like this. I can't keep stealing like this, either."