Heart of the Swarm Campaign- Dominion Space: Conviction (Part 4)

Head Southwest across the retractable bridge and wipe out a small garrison force backed up by a thor, then turn to the Northwest.  The next room includes a siege tank and several goliaths, but another delivery will supply you with an additional aberration and set of zerglings to bolster you from any losses suffered here.  Break the door to the Northwest with an assault to continue further into the ship.

Deal with a squad of foot troops and a siege tank in the next room, with the unwitting aid of a number of Terran convicts who are unwilling to die with the ship if it means staying imprisoned.  Continue Southeast through another corridor to reach an ambush by six reapers, who should be crushed rather quickly at this point.  Another small garrison is past the end of the hall, and as you take them out a small squad will flee to the Southwest.  Don't bother chasing them- if you head Southeast first, you can go up a ramp to pick up the other half of your bonus objective quickly.  Then turn to the West and the end of the level- which is blocked off by a bulkhead and the same squad that was trying to escape.

Bust through the bulkhead with a full assault, and you can face the last of the Dominion forces- primarily a couple of bunkers and a siege tank that's in artillery mode.  Once the defenders are destroyed, partly with the aid of another leviathan drop, Sarah will direct the leviathan to stabilize the cell block with its tentacles.  Finally, Kerrigan will rescue James Raynor from Arcturus' Dominion forces.

The rescue is sadly bittersweet, though- although she has rescued her loved one, she has done so as Sarah Kerrigan, Queen of Blades, not as a human being.  The results could be bad, but she leaves her life in Jim's hands as a symbol of trust- and to allow him his choice of how he feels about what Sarah felt she had to do.

While he does not kill her, it is clear that he does not agree with her assertion that this is what she had to do...