He was treated as a cat treats a mouse; he was worried, confined, disgraced, publicly reprimanded, brought just within verge of the charge of treason, but not quite, just enough to discredit and alarm him, but to leave him still a certain amount of play.

He was made to see that the Queen's favour was not quite hopeless; but that nothing but the most absolute and unreserved humiliation could recover it.

It was plain to any one who knew Essex that this treatment would drive Essex to madness.

"These same gradations of yours"-- so Bacon represents himself expostulating with the Queen on her caprices--"are fitter to corrupt than to correct any mind of greatness." They made Essex desperate; he became frightened for his life, and he had reason to be so, though not in the way which he feared.
At length came the stupid and ridiculous outbreak of the 8th of February, 1600/1601, a plot to seize the palace and raise the city against the ministers, by the help of a few gentlemen armed only with their rapiers.

As Bacon himself told the Queen, "if some base and cruel-minded persons had entered into such an action, it might have caused much blow and combustion; but it appeared well that they were such as knew not how to play the malefactors!" But it was sufficient to bring Essex within the doom of treason.
Essex knew well what the stake was.