A plot to put a CHEMICAL WEAPON!!! in London.
But, strictly speaking ... Alastair Hay, Professor of environmental toxicology at Leeds University, said osmium tetroxide was a rare catalyst and could potentially make an explosion occur more rapidly. [but] ... did not fit the profile of a typical chemical warfare or dirty bomb agent ...
"It would not be in the same category as some radioactive substance which would continue to emit radiation and cause a problem in terms of clean up," he said.
Shocked reaction and general "look at those evil terrorists" from the UK government.
The only question that seems vaguely worth asking is whether Blair and co.
a) kind of hoped this wouldn't happen, but decided the risk was worth taking, in order to defend the principle of pandering to Bush's obsession with Saddam and giving Middle-eastern oil reserves to Halliburton.
b) ... like, didn't realize, and mistook invading Iraq for something to do with reducing terrorism.