Heart of the Swarm Campaign- Skygeirr: Infested (Part 2)

During the three minute gas release, the Dominion forces will launch an assault against your first virophage, so you will want to move out  your main forces to destroy the attackers and bring the attempt to a halt.  Try to be quick- you have limited time before you need to move on and the virophages are unfortunately fragile.

Once the gas release ends, you will have about four to five minutes to move about with the infested Terran forces supporting you before another three-period gas attack.  This pattern will repeat for the rest of the mission.  Each time a gas attack is launched, the Dominion forces will move out at least one squad of medevac-transported troops and a few assault vehicles to attack your virophages.  If you're quick and careful, you can take over the majority of the enemy vehicles for your own use, and still keep your virophages intact- a good rule of thumb is to plant spore colonies around the virophages, forcing enemy vikings to land before reaching them and then take the long way- running across the front of your forces and likely right into your infestors.

The fourth virophage location is immediately North of the third, and protected by an entrenched siege tank and some troop facilities- the siege tank is difficult to take control of, as it's been surrounded by missile turrets that can spot your burrow-traveling infestors and get them blown up.  Don't worry about it too much- just capture the point as soon as possible, then move on to the due East and grab a fifth garrison.  This should be about as far as you get between gas releases, unless you're especially fast.

During the second gas release, the infested Stukov will highlight three locations on your map- these are the science facilities where the Dominion forces have been studying and researching the Hybrid units, and are where you'll gain your bonus levels for Kerrigan.  Thankfully, all three of them are right along the route you're going to want to take in clearing out the Terran forces and implanting virophages, so they aren't even remotely a hassle to deal with- you may even find yourself getting some help from the 'automated' infested troops your virophages produce.