Even though he was only 4 years old at the time, Vashi Nedomansky has vivid memories of that day in 1974 when his parents took him aside and told him they would be clandestinely leaving Czechoslovakia to start a new life in Canada.

Named Vaclav after his grandfather and father but called Vashi much of his life, he took to the street shortly thereafter and began chanting, "Canada! Canada!"

"That was kind of dangerous," Vashi said. "They said, 'No, you can't say anything about that.'"

By then, their phones were already tapped and secret-police surveillance came daily. Typical treatment in Cold War-era Czechoslovakia for one of the world's best hockey players.

What followed was the first true defection in hockey history and one of the sport's most surreal careers. It's a story that hasn't been told completely but will in an upcoming documentary called "Big Ned," with Vashi serving as chief storyteller alongside his father.

"In the past, I never really showed anyone or told anyone my history. This is probably the time to properly do it," said Vaclav, 72. "I never felt comfortable doing that. My son is a filmmaker and we are close and we just started talking."

Those conversations began three years ago, when Vaclav experienced medical problems so grave that doctors gave him, at best, a 50-50 chance of survival. But after he pulled through, he decided it was finally time to discuss his career.

Vaclav's legend in his home country was cemented at the 1969 World Championships, when he led Czechoslovakia to two wins against the tournament's eventual winner, the Soviet Union. Those wins provided a measure of revenge after a Soviet-led invasion of Czechoslovakia to suppress the Prague Spring, a 1968 uprising against Russia that would inspire Jaromir Jagr to wear No. 68.

Vaclac Nedomansky, along with wife Vera and son Vashi, fled Cold War-era Czechoslovakia for Canada in the first defection in hockey history Don Dutton/Toronto Star/Getty Images

By the time he was named the top forward at the 1974 Worlds, Vaclav was ready to leave his oppressive communist surroundings in search of a better life in North America.

Nedomansky acquired a two-week visa and drove his family through Austria to Bern, Switzerland, where they stayed at the home of Jarda Krupicka, a friend and former teammate. From there, Nedomansky plotted his defection to Canada, but it wasn't long before the family realized they were being tracked by government agents.

Within days, journalists from around the world, including legendary Toronto Sun columnist George Gross, himself a defector from Czechoslovakia, began calling the house. Gross would later win a national newspaper award for the piece he wrote about Nedomansky's defection.

Vaclav eventually reached out to his father, who didn't know his son was defecting. Of course, by then it had become obvious that Vaclav and his family wouldn't be returning. Within days of their exit, their home had been swarmed by government agents who had confiscated many of the belongings they had left behind.

With government agents fast on their trail, the family made it to Switzerland before arriving in Canada lacking any familiarity with the local language or customs.

"If you look at the photos of communist Czechoslovakia in the 1960s and '70s, everything is literally gray," Vashi said. "Mute tones, desaturated colors. The second we landed in Montreal and Toronto, it was a fanfare of colors and music and sounds that I had never experienced before. [In Czechoslovakia], there was no rock and roll, no McDonald's. [The new experience] was overwhelming. A feast of sensations once we got there. My dad really loved that."

Vaclav Nedomansky defected from Czechoslovakia to play for the WHA's Toronto Toros. Getty Images

Though Vaclav was thrilled to have his young family, which would later include daughter Anandi, beyond the grasp of Czechoslovakia's communist government, his struggles didn't end with his arrival in North America.

Vaclav was immediately labeled a traitor in his home country and was effectively erased from that nation's sporting history books. This despite being one of the greatest athletes in Czechoslovakian history and an inspiration to future stars such as Peter, Anton and Marian Stastny, who all defected to Quebec in the early 1980s.

Vaclav also had little interaction with the friends and family he left behind -- an unnerving prospect considering how vulnerable they were at the hands of a spiteful communist regime known for punishing the families of defectors. Nedomansky's father became a prominent target of the police.

"They were called by the police and asked if they knew something. They tried to convince them to send them to see me and try to get me back and all that stuff," Vaclav remembered. "They couldn't travel or anything." (Nedomansky's father, terminally ill, was granted a visa to travel to Canada in 1984, 10 years after his son's defection. They enjoyed a two-week reunion before he died.)

But being in North America didn't necessarily mean Nedomansky was beyond the grasp of the Communist party. When the Toronto Toros opened the 1975-76 season with exhibition games in Scandinavia, the team was alerted that Nedomansky could be in danger when he arrived in Finland, where the Communist party was quite powerful at that time. For his own safety, Nedomansky spent a few extra days in Ornskoldsvik, Sweden, while the rest of his team played in Finland.

Struggling with a new culture in Canada, everything was new and unusual for the Nedomanskys. Ideas as novel as traveling freely and being able to shop in fully stocked grocery stores were a revelation. As were Vaclav's talents to fans in North America.

"I most struggled with the language. I spoke German and Russian, but never the English language," Nedomansky said. "Fortunately enough, I didn't need the language as long as I was playing well. That was important in my transition."

Vaclav Nedomansky (back row, middle) is a scout for the Predators and also for the Team Euro entry in the World Cup of Hockey. Melynda Pilon/NHLI/Getty Images

An instant star with the World Hockey Association's Toros -- he scored 96 goals in two seasons and won the WHA's equivalent of the Lady Byng Memorial Trophy -- Vaclav's career took an unexpected turn when the team moved to Alabama and became the Birmingham Bulls. But everything came together in 1977, when Vaclav was dealt in a rare inter-league trade to the Detroit Red Wings, where highlights included 38- and 35-goal seasons. He would finish his NHL career with 122 goals and 156 assists for 278 points in 421 games (he had 253 points in 252 WHA games).

With that, the Nedomanskys found their home for the next 15 years and Vashi, now 45, found the passion that would fuel his current career.

"When my dad was playing for the Red Wings, he was [named] the first star of a game," Vashi said. "He won a Panasonic video camera and a tape deck. So he gave it to me. I started shooting short films around the house with my friends. I started shooting my parents on vacation. Because we had another VCR at home, I would cut from one deck to the other, so I could actually edit."

Vaclav's most trying period might have come after his retirement in 1983, when he sued his former agent, Alan Eagleson, for an alleged breach of his contract.

The longtime head of the NHLPA, Eagleson was the most powerful man in hockey at the time and won the $1.7 million lawsuit in 1984. For his trouble, Nedomansky was ordered to pay Eagleson's legal fees, which amounted to $60,000. Nedomansky would get validation, however, when in 1998, Eagleson pleaded guilty to six counts after being indicted on 34 separate charges ranging from racketeering to fraud to embezzlement and obstruction of justice.

Vashi tried to follow in his father's formidable hockey footsteps, attending the University of Michigan, where he played three years and took several film classes. After going undrafted, he spent a decade in pro hockey, primarily in the farm systems of the Los Angeles Kings and New York Islanders, before quickly launching his second career.

In recent years, Vashi has edited a variety of feature films ranging from "Deadpool" to "Gone Girl" to "Sharknado 2." All the while, friends encouraged him to make a film about his father.

"He has been sitting on this a long time. He's a very private person," Vashi said of his father. "He trusts me, so he allowed me to have full access."

"Big Ned," a documentary film directed and edited by Vashi, is poised for a 2017 release. The work is still in its early stages.

"His shots are real unique. I think he has a great feel for the film," said Vaclav, who worked as a scout for the St. Louis Blues and Kings, as well as with the Slovakian Olympic team before taking his current job as a pro scout with the Nashville Predators. He is also a scout for Team Europe at the upcoming World Cup of Hockey.

"He has a good eye for taking shots. He is also a musician, so he is mixing it with color and music. I think that's important. It's really nice."

For Papa Nedomansky, the hours of sit-down interviews have been an enjoyable, if overdue, stroll through a historic career. For his son, the project has been a revelation.

"I'm learning more about him and more about our family and me than I've learned in the last 40 years," Vashi said. "It's mind-blowing to me what I've been learning. Absolutely filling in the pieces that I had no idea about all these years."

Featuring interviews with NHL greats such as Paul Henderson, Frank Mahovlich and Dennis Hull, "Big Ned" is Vashi's first foray into a full-length documentary. It's also the long-awaited profile of an icon some believe should be inducted into the Hockey Hall of Fame. If the film can in any way also help serve that purpose, then it will be an even greater tribute from a son to his father.

"It's been emotional on certain levels," Vashi said. "It's been eye-opening. It's almost my journey, as well. It's my dad's choice to give his family a better life and opportunities to do things, and I'm the one directly benefiting from his decisions.

"I'm now even more appreciative and grateful for this chance to follow my dreams. Being able to harness my power and energy and give back to my dad and tell his story is the ultimate honor."