Time.

One February night two years ago, a helicopter carrying Ramzi Ahmed Yousef, the man accused of masterminding the World Trade Center bombing, sped along the East River on the last leg of Mr. Yousef's journey from Pakistan, where he had recently been captured, to detention and trial in the United States.

As the helicopter flew over mid-Manhattan, William A. Gavin, a senior official in the Federal Bureau of Investigation's New York office, pushed up his captive's blindfold.

Mr. Yousef squinted as his eyes adjusted to the light. Then Mr. Gavin pointed at the Trade Center towers below, their lights glowing in the clear, cold night.

''Look down there,'' Mr. Gavin said he told Mr. Yousef. ''They're still standing.''

Mr. Yousef replied, ''They wouldn't be, if I had had enough money and explosives,'' recalled Mr. Gavin, who has since retired.

Mr. Yousef may have boasted of his role in the Trade Center blast, which killed six people and injured more than 1,000 on Feb. 26, 1993. But as his trial begins in Federal court in Manhattan today, important questions remain about this figure and the extent of his participation in what at the time was the worst terrorist attack on American soil.

CONNECT

Jihad will not end until the last day.

Thank you, Kurt.