Sentence:  Besides some care is taken, so far as conveniently can be, both to give regard to the further spring of any matter tending to the entry or execution of any other or evil <WSD>plat</WSD>, and also upon the sight thereof, to have timely recourse to the King, to warn him and others to beware and provide for the seasonable prevention of the danger; [...] 
Meaning of the word marked with <WSD> tags:  A plot, a scheme.