Heart of the Swarm Campaign: Kaldir -Shoot the Messenger

Your second mission on Kaldir is to intercept several Protoss preparing to launch and travel to Shakuras so that they can warn the greater Protoss forces and come slay all the Zerg present.  This mission offers you access to hydralisks, the evolution mission for zerglings, and up to three additional levels for Kerrigan should you accomplish the side goals.

Kerrigan sets things rolling by destroying the shuttle already en route to the conduit with the aid of several hydralisks that were left behind.  You are then taken to your main base, to begin building up forces.  With hydralisks now available, you have been granted the necessary anti-air offense to take down the shuttles without an excessive investment in the frail queens that have so far been your only unit which can attack air.

Begin building up resources and control immediately, and you can send Kerrigan out with the hydralisks and roaches you began with to rescue two additional hydralisks from the area to the Northwest.  To the North of your base is a small Protoss encampment- approaching it from the North by looping around the ravine will let you eliminate the pylon with Sarah's Kinetic Blast and then use Crushing Grip to disable the defenders so that they can be killed with no risk.  If you search around you will also locate a second conduit to the East of your base- it is a good idea to begin extending your outpost and creep in that direction so that you can park spore colonies outside of it just as you have one by the first conduit- and a second spore colony you can quickly move in to guard there as well.

Immediately, a second shuttle launches from a Protoss base on the extreme North of the map- you have a good deal of time thanks to the ship's horribly slow movement rate, but don't get too lax- attacking it only when it's near the conduit is risky, and you can easily move Kerrigan and some hydralisks up to the North to intercept a short distance away.

After a short while longer, Eisha informs you of several stasis chambers nearby where the Protoss colonists have been storing various lifeforms- forms with DNA that can be used to better Kerrigan.  There are three locations- one almost due North, one close by to the Northeast, and one further to the Northeast.  The closest will be fairly easy to reach, but be cautious and don't overextend your forces trying to get there- the Protoss will soon go on the offensive, trying to break your defenses around the conduits.