On the first level of the third episode (Counterstrike), instead of building and deploying a Military Base (as briefing suggests), build up a full fleet and attack the Kariak planet (Khiirzask Prime). As you got near, the objectives will change into conquering the planet. Doing so will skip the next level (Taking Khiirzask). The same trick of skipping works with the first level of the fifth episode(Darzok intrigue): by helping the Kariak Government in defeating Mohr'Thep will skip the next level (Rebirth of the Kariak Empire). Both of them makes sense, because the skipped levels are consisting of doing the same.