The first note of this episode goes to the music: very appropriate and definitely gives an intense feel and sense of foreboding. The next nod goes of course to Kate Mulgrew as this is the most forceful and driven we have seen her in a long time. I really do mean driven: the victory-at-any-cost-and-heck-with-any-other-view, type of driven we see again two seasons later, but here she pulls back and listens before the final moment as opposed to watching the reality unfold at her opponents death.
The conversation Chakotay has with the captain in sickbay and the Borg (seven) in the ready room are not exactly intense but the are central and vital to the episode, not to mention cool; don't miss them. To find the meaning of the episodes title and the code word "scorpion" you will have to watch part one, which is pretty much as good as this one.
The only problem I have with the episode is that we find out a season or so later that the "enemy" they unite against was not and is not an invading force as it is displayed and nearly flat out stated in this episode. ("'your galaxy will be purged' sound familiar?") side note this is Kes' near finest and near final hour, keep that in mind. 4 out of 5 stars.