The “9/11 Truthers” are a group of individuals who believe the government was aware of, or even contributed to the attacks on September 11th, 2001. The popular belief is that these attacks were carried out by Al-Qaeda, an Islamic terrorist group.
The Author presents a hypothetical situation wherein he proposes a merged theory that compromises between the truthers and that of popular belief - one tower was destroyed by the government and the other by Al-Qaeda. The hypothetical outcome is that the truthers are not pleased with this idea.