Its scope was ruthlessly ambitious, causing destruction officials say would have been “unimaginable.” The alleged plot to take down several U.S.-bound planes with liquid explosives appears to be unlike anything the world has seen in years. Counterterrorism officials said Thursday the London plot appears to bear the fingerprints of al-Qaida, and may have been “the Big One” they have been dreading since Sept. 11, 2001, particularly as the five-year anniversary of the carnage approaches. Full Story