A group of Marines � The first group of Marines can be eliminated with Kerrigan and her active skill Cloak. In this mission, only hidden turrets and defensive systems can detect her.
The Long Corridor � Having destroyed the solitary soldiers, let cloaked Kerrigan go through the door at the end of the corridor. The rest of your forces should wait before the door until the next room is cleared. Keep your units in the upper side of the corridor, as there are enemy units on the upper level.
Room with Goliaths � There are several Goliaths, heavy Terran units, in this room. You can easily take them out with cloaked Kerrigan. Only then lead the rest of your Zergs inside. Otherwise, there will be heavy losses.
Ghost's position. � There is a Ghost just above the stairs, which can shoot at your units unpunished for a long time while they are busy battling the Marines. Send in Kerrigan first to take it out, then have the rest of your soldiers deal with the Marines.
Corridor with hidden turrets � There are several turrets here, that will activate on timer. Usually when a units finds itself in the middle of the corridor. The turrets themselves have low HP and attack, but they make up for it with numbers. Kerrigan will be detected either way, so you can use this skirmish to replenish her Energy reserves.
Trapped Zerglings � Once you approach this locations, the Marines will start shooting at a group of Zerglings trapped below their position. If you're fast, you can save most of them. You'll gave to reach the nearby Marker to open the door leading to the room.
A group of turrets and defenders � There's a group of Marines and three turrets just around the corner. You'll have to attack with everything you got, as Kerrigan will be detected. You can try to lure some of the enemies by using a Hydralisk as a bait. You cannot bypass this spot, nor deal with it any other way.
Two groups of Firebats � Attacking the Firebats with your main forces will end with either a defeat of staggering losses. Just send cloaked Kerrigan to deal with them.
Room - Terran ambush � A moment after you enter the room with the open door and several Marines inside you'll be ambushed. Enter with all your forces, not just Kerrigan. There will be Marines, a Ghost, and a turret on the hill. Once you deal with the, activate both Markers.
Teleport - entrance � This teleport will transfer you to a new location. First, though, you'll have to deal with a turret and three Firebats just above the stairs. Bring in the Hydralisks to take out the turret, and when the enemy is dealt with, send Kerrigan through the Teleport.
Teleport - exit � Send Kerrigan first and clear the hill of enemies. Only then you can bring the rest of the Zerg.
Mission objective � The most difficult battle of this mission. If you haven't saved most of your Zerg forces that you got at the beginning of the mission, you may have a problem with taking out the last group of enemies. There will be a hidden turret and several Ghosts. First, send your forces to take out the turret. Sometimes enemy troops may block the stairs, but the position of the turret will be revealed. Hydralisks should always focus on attacking the turret.