Credit: Metropolitan Police via Getty Images

(CNN)--The nightmare Charlie Rowley experienced began the day he picked up what seemed like an ordinary perfume bottle. Eight years later, he still struggles to express what happened. In a new documentary produced by CNN Films titled "The Salisbury Poisonings: A Spy Next Door," premiered on CNN Sunday, Rowley tells his story alongside others whose lives were changed forever by those attacks. He often stops speaking mid-sentence, his eyes welling up with tears.

It happened on a summer afternoon in the town of Amesbury, England. While rummaging through a charity donation bin, he spotted a small cardboard box. Inside, he found a plastic-wrapped container bearing the label "Nina Ricci." Convinced that someone had discarded an expensive French perfume bottle, he took it home to surprise his girlfriend, Dawn Sturgess.

Finding treasures among discarded items was one of his favorite hobbies; over the years, he had retrieved televisions and other household items. But on that day in June 2018, he hoped someone had thrown away a ring he could use to propose to her. He told CNN in a recent interview: "She always talked about wanting an engagement ring... a ring with a blue sapphire."

He did not know the bottle contained the same nerve agent that investigators believe Russian operatives had used three months earlier to poison a former spy in nearby Salisbury. What followed was a tragic chain of events that killed Sturgess and hospitalized Rowley, making them collateral victims of an international spy story involving an assassination attempt on a double agent.

He recalls: "I thought it was a real and nice gift, and she was happy to receive it. But things went tragically and very fast. She sprayed the perfume, inhaled it, and put some on her wrist. Shortly after, she said she felt strange. She complained of a headache... then she stopped responding altogether. I tried to revive her, and everything seemed to happen in slow motion."

Later that day, Rowley was sweating, rocking back and forth, and muttering unintelligible words, as the poison—later identified as Novichok, a Russian nerve agent—was also ravaging his body. Rowley fell into a coma and was hospitalized for weeks, noting that at first he did not remember exactly what happened. After being discharged, he suffered a stroke that put him back in the hospital for another long period.

This ordeal thrust Rowley—who was unaware of the truth—into the midst of a conflict between Russian and British intelligence agencies. Rowley said: "Who knew a spy lived in Salisbury? It was a shock. And who would think that toxic substance would reappear inside a bottle?"

He told CNN: "I tried to push those memories out of my mind. I never expected this to happen to me or to Dawn. Since then, things have never been the same."

He noticed something unusual about the bottle. The couple had been dating for about a year after meeting at a homeless shelter, where Sturgess was staying. Rowley had just moved into a new home and was setting it up for Dawn to move in with him. Their lives revolved around simple pleasures, including the "treasures" Rowley retrieved from charity donation bins outside public places.

He said: "There was a bit of social embarrassment about being seen rummaging through donation bins, but it paid off most of the time. I always found something, big or small. And anything nice I found went straight to Dawn. I always dug to the bottom, hoping to find that ring."

In their spare time, the couple listened to music and watched movies; Sturgess loved Bob Marley and action films. Rowley said: "She wasn't very into light romantic movies. Sometimes, if the traveling funfair came to town, we would go and wander around the stalls and have a good time."

Then a kind gesture led them down an unforeseen path. On June 28—two days after Rowley found the box in the donation bin—he gave it to Sturgess. It happened on a Saturday around noon; they were watching TV after spending the previous day at Queen Elizabeth Gardens, a lush riverside park overlooking Salisbury Cathedral with Britain's tallest church spire rising above the trees.

Rowley recalled that she recognized the brand immediately and seemed excited. He remembers wondering why the spray nozzle was detached and not attached to the bottle, and that he had to remove the cap and attach the nozzle himself.

Sturgess sprayed the substance, sniffed it, then dabbed a bit on her wrist. The substance was oily and had no scent. He recalls thinking then: "Very strange; perfume without a smell."

Shortly after, she told him she didn't feel well and went to the bathroom, where he heard a thud. He found her unconscious in the bathtub and called emergency services.

He said: "One moment I was talking to Dawn, the next moment she wasn't herself and passed out. I was in a state of sheer panic, and I didn't know what to do."

Paramedics rushed Sturgess to the hospital. Unaware that she had been poisoned and that it was linked to Russian espionage, Rowley decided to run some errands before joining her there.

He said: "I wish I had gone with her. I was planning to pack a small bag for her with some simple things, some clothes, toiletries or the like, for her to take to the hospital. But everything happened so fast."

He never saw Sturgess again. Five hours after her collapse, an ambulance returned to the same address to pick up Rowley, who had fallen ill after returning home.

Sturgess died 10 days later, while Rowley was in a coma. She was 44 years old.

Neil Basu, former head of the UK's counter-terrorism police, says in the documentary that the small bottle contained enough poison to kill 10,000 people.

Poisoning of a Former Spy in the Vicinity

The charming and picturesque city of Salisbury—with a population of about 44,000—seems more like a postcard setting than the center of an international espionage scandal.

The case unraveled like a scene from a spy novel: on a cold March afternoon in 2018, two people were found lying motionless on a bench in a shopping center in the city center.

Investigators identified them as Sergei Skripal, a former Russian military intelligence officer convicted of spying for MI6, and his daughter Yulia, who was visiting from Moscow. The police officer who first found them was also taken to the hospital.

Rowley said, as if still struggling to believe it even eight years later: "We had a spy in Salisbury. The city was hiding secrets."

Within days, British investigators concluded that the two had been poisoned with Novichok, a nerve agent developed by the Soviet Union.