The rift continued to deepen, and Danielson says she was rarely consulted on decisions, even though the company’s core was composed of only a handful of people at the time. "It looked like Antje was not being brought into the discussions," says Paul Covell, a product manager at Google who was Zipcar’s first engineer. "There were more conversations happening without her than with her." Roy Russell, Chase’s husband and Zipcar’s founding technology officer until 2006, says that happened because Danielson wasn’t fully committed to the company. "She never took on a real strong operational role at the company, that I can remember," he says. "In some sense, I am not sure she ever joined [the company], in the sense that she never left her other job at Harvard." But Danielson doesn’t see things that way. "I worked very hard," she says. "I did work my regular hours at Harvard — my 35 hours a week — and then I worked an additional 30 hours or so per week doing Zipcar."

According to the majority of Zipcar staff interviewed for this story, Danielson’s strengths didn’t work in her favor. She was an astute academic and a passionate environmentalist, but one without a shred of business experience. "Antje brought a more earthy, holistic view to the company," says Mark Chase, Robin’s brother and the director of business development at Zipcar for four years. Larry Slotnick, a former fleet manager at Zipcar who oversaw large groups of vehicles, puts it more bluntly: "It wasn’t like she was doing any irreplaceable task." Slotnick recalls Danielson as easy to work with, but says she had trouble balancing professional and personal duties. "She just wasn’t one of these co-founders who was able to put in 50 or 60 hours a week," he says.

But Covell says that Danielson focused on Zipcar even after the birth of her second son in 2000. "Antje remains somewhat unique in my experience because when she had her second child, she didn’t miss a beat at the office at all." Danielson herself remembers going out at midnight to jump-start a Zipcar with a dead battery, "and I did that with my infant in the car seat."

Though the rift between the two founders was obvious, its extent was unclear until early January of 2001. During a board meeting, Chase petitioned Zipcar’s board for the ability to make hiring and firing decisions without consulting them. Danielson thought it was a reasonable request that would make things easier as the company expanded, so she voted for the proposition, which passed. "Two hours later, she was firing me," Danielson says. "Robin wanted to be the sole powerhouse in the company, and she was very savvy at getting the power." Covell says he didn’t see it coming. Even Chase’s brother was surprised. "All I know was that Robin initiated it with the board, and that it was some kind of power struggle," Mark says. "I was shocked when it happened." Only weeks earlier, Danielson had given her notice at Harvard to work full-time for Zipcar. The impending end of her career in academia made the initial shock of her firing at Zipcar all the more devastating. "I had the idea, I started it, and I asked Robin to partake," she says. "It was almost as though a baby had been taken away from me."

Chase has often stated in interviews that Danielson decided to leave Zipcar on her own. But the former Zipcar CEO now says that she avoided expanding on Danielson’s departure because of a deal the founders struck following the boardroom incident. "I have spent the last 14 years honoring the agreement I made with Antje when she left the company," she wrote in an email. "This includes not disclosing these details."

"I have worked very hard to protect Antje over the years, whether or not she appreciates that."

When presented with Danielson’s account of the firing, Chase called it "fascinating." The board meeting, she wrote, made clear that the board's responsibility was to never meddle with the operations of the company. "I definitely did not ask the board if I could have the right to fire people in order to fire her," she said. "I have worked very hard to protect Antje over the years, whether or not she appreciates that."

Danielson left Zipcar quietly, taking a job at Harvard’s Green Campus Initiative. She has never spoken publicly about the circumstances surrounding her departure. "I didn’t make a fuss because Zipcar was still in a very vulnerable state," Danielson says, "and I didn’t want to run it into the ground." Danielson owned shares in the company, but asserts that a potentially lucrative payoff wasn’t what kept her from speaking up. "You don’t kill something just because someone else isn’t taking their ethics classes."

After the firing, however, the company dynamics were largely unchanged, Slotnick says. "It’s not like we dwelt on it for a long time," he recalls. "I don’t think it had too much of an impact." The company kept expanding, extending its reach to New York City and Washington, DC, within the next two years. But Covell recalls the immediate aftermath of Antje’s departure as sorrowful rather than business as usual: "I remember it being a pretty dark situation."

Danielson remained a Zipcar shareholder until Avis bought the company in early 2013. "I started off with 50 percent of the company," she says. But after multiple rounds of funding, she ended up with 1.3 percent — about $6.3 million in an acquisition worth $491 million.

Two years after Danielson's firing, Chase was no longer at Zipcar. In the past, Chase has claimed she left Zipcar because of her father’s recent death and her daughter’s budding modeling career (her daughter is Victoria’s Secret model Cameron Russell). And when The Verge asked if she was fired, Chase answered that it was "a very complicated and long story," and she was "not interested in engaging." Some within the company simply say, much like Danielson, that she was forced out. "It was the board’s decision," Slotnick says. "Robin was trying to bring some venture capital — the next infusion of money — and she was having a hard time doing it." According to him, this was one of Chase’s first efforts to raise millions of dollars on her own, and the people she approached could tell. "She was the one responsible for bringing in the dough, and she didn’t make it happen." Based on that, he says, the company’s board decided they wanted a different CEO.

"My feeling was that Robin was never given a chance — they just orchestrated a take-over and that was that."

Chase was a charismatic leader, says former Zipcar engineer Greg McGuire, but she had a hard time infiltrating the boy’s club that governs the venture capital world. "It’s almost exclusively males," he says, "and it’s difficult to break into that." When Chase’s successor Scott Griffith took over, the funding immediately started coming in. "It kind of seemed to me like the VPs involved were withholding closing on that round [of funding] until they were able to execute the changes they wanted," McGuire says. "My feeling was that Robin was never given a chance — they just orchestrated a take-over and that was that."