(Nice timing! I just read this passage a week ago…)
This is from the opening to the War with Catiline.
Igitur de Catilinae conjuratione quam verissume potero paucis absolvam; nam id facinus inprimis ego memorabile existumo sceleris atque periculi novitate.
Therefore, I'll give a short summary of the conspiracy of Catiline, as truthfully as possible—as I, personally, consider this issue especially relevant due to the novelty and danger of the crime.
Sallust's intentionally-archaic style is exhausting to read, but I've tried to be somewhat literal here. Alternately, one might render it as Ye Olde Butcher'de Englishe:
And ergo, regarding the Conspirasie of Catilina, I shall forthwith recount, as verily as I may be Capable, for I, myself, indeed, do believe this Crime to be so especially Heinouse, both due to its Noveltie, and due to the great Dangere it hath Prodused.
This might be a bit unfair to a famous historian, but I'm not sure how else to represent the use of verissume, inprimis, and existumo in the first century BCE.