When an admitted Al Qaeda operative planned his itinerary for a Christmas 2009 airline bombing, he considered launching the strike in the skies above Houston or Chicago. But tickets were too expensive, so he refocused the mission on a cheaper destination: Detroit.

The decision is among new details emerging about one of the most sensational terrorism plots to unfold since President Barack Obama took office. It shows that Al Qaeda's Yemen branch does not share Osama bin Laden's desire to attack symbolic targets, preferring instead to strike at targets of opportunity. Like the plot that nearly blew up U.S.-bound cargo planes last year, the cities themselves didn't matter. It's a strategy that has helped the relatively new group quickly become the No. 1 threat to the United States.

After the failed bombing and the arrest of suspected bomber Umar Farouk Abdulmutallab, the question of why Detroit was targeted had gone unanswered. It was previously reported that Abdulmutallab did not specifically choose Christmas for his mission.

Abdulmutallab considered Houston, where he attended an Islamic conference in 2008, current and former counterterrorism officials said. Another person with knowledge of the case said Abdulmutallab also considered Chicago but was discouraged by the cost. All spoke on condition of anonymity because they were not authorized to discuss the case.

While the target and timing were unimportant, the mission itself was a highly organized plot that involved one of the FBI's most wanted terrorists and Al Qaeda's go-to bomb maker, current and former officials said. Before Abdulmutallab set off on his mission, he visited the home of Al Qaeda manager Fahd al-Quso to discuss the plot and the workings of the bomb.

Al-Quso, 36, is one of the most senior Al Qaeda leaders publicly linked to the Christmas plot. His association with Al Qaeda stretches back more than a decade to his days in Afghanistan when, prosecutors said, bin Laden implored him to 'eliminate the infidels from the Arabian Peninsula'.

From there he rose through the ranks. He was assigned the job in Aden to videotape the 1998 suicide bombing of the USS Cole, which killed 17 sailors and injured 39 others, but fell asleep. Despite the lapse, he is now a mid-level manager in the organization. Al-Quso is from the same tribe as radical U.S.-born cleric Anwar al-Awlaki, who had an operational role in the botched Christmas attack.

In December, al-Quso was designated a global terrorist by the state department, a possible indication that his role in Al Qaeda's Yemen franchise has grown more dangerous.

Al-Quso was indicted on 50 terrorism counts in New York for his role preparing for the Cole attack and served more than five years in prison in Yemen before he was released in 2007. On the FBI's list, al-Quso ranks behind only bin Laden and his deputy Ayman al-Zawahiri among the most sought-after Al Qaeda terrorists.

After meeting with al-Quso, Abdulmutallab left Yemen in December 2009 and made his way to Ghana, where he paid $2,831 in cash for a round-trip ticket from Nigeria to Amsterdam to Detroit and back.

Abdulmutallab, 24, is charged with attempting to use a weapon of mass destruction and conspiring with others to kill 281 passengers and 11 crew members aboard Northwest Airlines Flight 253. After his arrest, he admitted to the FBI that he intended to blow up the plane and later surfaced in an Al Qaeda propaganda video.

Abdulmutallab initially cooperated with investigators, pulling back the curtain on some activities by Al Qaeda in the Arabian Peninsula, the Yemen-based offshoot that has quickly became Al Qaeda’s most active franchise. Plea discussions fell apart, however, and he's scheduled to go to trial in October while acting as his own lawyer.

One of the challenges facing U.S. intelligence officials is that much of the information they collect on terrorists comes from surveillance or informants, and the government is reluctant to reveal it. So if a terrorist is captured overseas, prosecuting him in the U.S. or persuading another country to hold him can be difficult.

A plea deal from Abdulmutallab would have resolved that dilemma. His testimony could form the basis for indictments against al-Awlaki or perhaps bomb maker Ibrahim Hassan al-Asiri. And the U.S. wouldn't have to disclose some of its most sensitive intelligence-gathering techniques.