Heart of the Swarm Campaign- Dominion Space: Conviction

The second most reward-heavy mission in the game, Conviction is the quest to rescue Jim from the Dominion holding cell.  Successfully freeing him will grant Kerrigan a whopping nine levels in addition to the evolution mission for the swarm hosts, and bonus objectives can tack an additional two levels onto Sarah's total.  It's just a shame that such nice rewards are attached to a mission with such a sad element to it.

Regardless, Jim has been located on the Moros, a prison-ship that jumps from location to location throughout the galaxy.  The ship has stopped to refuel at Atlas Station, but will only be there for a limited time.  With only the support of the Zerg delivered to her by the leviathan, she's got to break through all the defensive forces on the Moros and release Jim from his cell.

From the starting room, you'll need to head to the Northeast.  A defensive force is waiting just through the doorway, so make sure you use Kerrigan's abilities to strike first.  Once you are in close with that group, another leviathan tentacle will breach the West wall and deposit some zerglings and hydralisks for your use.

With the first group out of the way, continue Northeast to face down a second batch of defenders and pick up some roaches and a queen.  However, the defenders have retracted a bridge behind them as you attacked.  This leaves the way forwards unpassable, forcing Kerrigan and the zerg accompanying her to the Northwest.  A weaker defensive force composed mostly of marauders and marines waits here, accompanied by a missile turret just in case.  Take them all out before heading up the ramp and into a prison bay.  Taking out the enemies here will prompt the delivery of some zerglings and an aberration, which immediately come under attack from incoming enemy hellbats.  Proceed down the ramp to the Northeast through the enemy troops and then hang a right, coming down Southeast towards the area where the bridge used to reach.