"In the Shadow of Death: Jason's Journey" is a multi-part "CBS Evening News" series that follows Jason Amaral, a 30-year-old addict living in the Boston area, on his path to recovery. See Part 2 on Tuesday at 6:30 p.m. ET.

BOSTON -- "Your eyes open, you think about heroin. Nothing else, nothing else," says Jason Amaral.

"And any addict that's watching this will like ... will attest to that. And if you don't have money, you're thinking about how to get money to get heroin immediately."

It was the day before he was to start rehab.

Jason's hunt for heroin began at 7:30 in the morning on a brisk day in downtown Boston. He allowed our cameras to follow him as he tried to get money to get high.

Jason calls his aunt asking for money so he can buy more drugs CBS News

From a parking garage, he called his Aunt Beth in Florida begging for cash.

"Can you send me $30 dollars? Believe me this is the last time I'm doing this to you," he told her. "If this doesn't work this time, I don't know what I'm gonna do. I'm serious."

He hopped on a train to meet a friend who gave him a few pills of Klonopin, an anti-anxiety medication known to addicts to take the edge off the urge.

He searched for a bathroom where he could crush and snort his pills.

"Since we're in such a high drug area, they don't let people use the public bathrooms," he explained.

So Jason went for the one building he knows is always open to the public: City Hall.

"I hope they don't check my bag," he said.

Once inside, he headed for a basement bathroom and put the money his aunt sent from Western Union to use -- using it to snort the mashed up pills.

Jason used money from his aunt to snort crushed up Klonopin pills in the City Hall bathroom CBS News

Around noon, we met Jason on the street after he scored more drugs from friends.

"I just did some heroin, and I was sick," he told us.

"I just did a shot and I'm very, very high, and I feel great. And I'm gonna go do what I need to do to make money, you know what I mean? That's just how it is."

But Jason's life wasn't always like this. He grew up in Needham, Massachusetts, with his younger brother Andrew. They were raised by a single mother, who by all accounts gave her boys a happy childhood.

But when Jason was only 11, his mom died from cancer. So the boys moved in with their father. In college, Jason started experimenting with the pricey pain pill OxyContin, which soon led to heroin.

And so began the life of an addict.

The morning we met him, he was on multiple drugs.

"Over the past three days what's in your system? What have you done?" we asked him.

"What have I done? Heroin, Klonopin, Xanax, cocaine, crack ... that's it."

By that evening, we found Jason at a friend's house. The two had scored some heroin mixed with the powerful drug fentanyl.

They prepared it while the friend's three-year-old child watched TV in the next room. Remember, the next morning, Jason was supposed to show up at a rehab center.

His phone rang -- it was his younger brother Andrew. Andrew is also an addict, who called to tell his big brother he was dropping out of a detox clinic.

"Don't leave, buddy. It's not a good idea to leave. Please don't," Jason begged. "I'm going to rehab tomorrow and I'm gonna stay."

But as he begged his brother to get help, he couldn't help himself. When he hung up the phone, Jason was overcome with emotion. But not for long. He continued with the heroin-fentanyl mix.

Over the next couple of hours, we watched as he nodded in and out, shot up again, snorted more pills, and saved some heroin for later.

Jason cries after getting a phone call from his younger brother, saying he was leaving a detox program. CBS News

By then, his best friend Mike Duggan arrived. Mike is a recovering addict who's been clean for seven years, and was taking Jason to rehab the next morning.

"It's life or death," Mike told Jason. "You will die if you don't get it this time, you know what I mean? It's just really what it comes down to."

The next morning, Jason, who has overdosed eight times and lived to tell about it, began the next chapter of his life.

If you or a loved one is struggling with addiction, resources are available. Visit one of the links below: