The 17 men and youths arrested on terror charges in Canada at the end of last week had plans that extended to storming the parliament buildings in Ottawa, taking over television studios and beheading the country's newly elected Prime Minister, Stephen Harper, it has been alleged.
Although prosecutors have still publicly to release all the details of their case, several elements surfaced during a preliminary court hearing on Tuesday. They suggested a plot that was more sinister and potentially destructive than most Canadians had thought.
The conspiracy, which appears to have been "home-grown", has also unsettled nerves in the United States, where there is fresh concern that Canada may have become a nursery for Muslim extremists who could strike at targets south of the border. In response, authorities in Washington this week ordered its agents along the border with Canada to be on high alert.
Canadian police, meanwhile, signalled that more arrests should be expected soon. They said they were also investigating whether the group had ties with terror groups in other countries, including the US.
The police moved in on the suspects, all Canadian citizens or residents of Canada, after determining that they were preparing to take delivery of three tons of ammonium nitrate, more than three times the quantity used to blow up the federal office building in Oklahoma 11 years ago.
However, a lawyer for one of the men said after the court hearings on Tuesday that the charges being filed against his client went much further. The lawyer, Gary Batasar, said his client, Steven Vikash Chand, 25, was innocent of the charges. "It's just generally speaking that the allegations are against my client as well as the other parties. That's what all the parties are facing."
The full panoply of the charges against Mr Chand and the other men - five of whom are under 18 and being treated as minors - may not become public until the first bail hearings for the men, which could take several weeks. Until then, the seriousness and sophistication of the alleged plot will not become clear.
Mr Batasar, however, said that an eight-page summary of the charges given to him on Tuesday showed the plot included plans to storm the Gothic revival parliament in Ottawa and take hostages, who were to be beheaded unless the government released Muslims in prison and withdrew its soldiers from Afghanistan.
Even more startling, however, was the charge that Mr Chand would "personally like to behead Prime Minister Stephen Harper".
"There's an allegation apparently that my client personally indicated that he wanted to behead the Prime Minister of Canada," Mr Batasar told reporters after the hearing in suburban Brampton, north of Toronto. "It's a very serious allegation. My client has said nothing about that."
Documents presented to the court also spelt out a plan to blow up an office of the Canadian Security Intelligence Service, CSIS, located at the foot of the CN Tower, the soaring landmark with a revolving restaurant in downtown Toronto. They also spoke of intending to take over the Toronto studios of the Canadian Broadcast Company, CBC, and to bomb power transmission lines.
Mr Harper, the conservative leader who was elected to lead Canada in January, brushed off news that he had been targeted. "I can live with these threats, as long as they're not from my caucus," he told reporters.
The Prime Minister also played down suggestions that the case was spreading alarm in the United States. The US ambassador to Canada, David Wilkins, paid tribute to Canadian investigators. "We appreciate the swift... action taken by Canadian law enforcement officials [who] stepped in decisively and I think helped defuse a very dangerous situation... and we frankly applaud their... heroic efforts."