If Khelgar is gone, then you have two choices:
1) Restart the game from before he went missing.
2) Copy the .ros File from another save(even a freshly created one) and use the console to modify his level and maybe gear to get him back to where he was.
This is a known issue from earlier patches, and for the most part fixed in the latest patches. Basically what happens is the file for a companion get corrupted and non-functional and so the game can't use it. When this happens everything usually works ok until the companion is needed for a cutscene and then it really starts breaking the game.
This is from the legacy forums tech help thread:
http://nwn2forums.bi...60311&forum=116
Post 8
First:
It should be noted that this particular bug has been fixed with the release of Patch 1.12 on March 19, 2008.
Second:
I have tested the update on a bugged saved game and I can verify that the update will NOT repair a saved game that had become corrupted prior to the release and installation of 1.12. Therefore, this post will remain for those who have as yet to patch their game to the latest update or may choose not to...
Since the 1.07Beta and the 1.10 patches, as well as the release of MotB, a couple of problems may seem to be more common. However, these are not new problems caused primarily by the recent patches nor the expansion, they have only been made more visible.
Apparently, a slight modification was done to the AI where the arcane classes, along with Druids and Rangers will, by default, automatically summons their appropriate Familiars or Animal Companions. Unfortunately these summoned critters are a problem when attempting to pass through transitions, either by player selection on the world map, or scripted as part of a conversation.
Some of the symptoms that may occur are Companions, such as Khelgar or Neeshka, may suddenly be replaced by Qara's familiar on the other side of the transition. In some cases, the game may hang or crash during or after a transition, or a conversation may not trigger on the other side of a transition.
One other thing that has been noted in a few posts is that it seems that if you lasso the party together using the Marquee function to move them all with the mouse and attempt a transition that similar issues of failure to transition, and may be an issue if you are using a Companion to initiate a transition. This can be avoided by selecting your PC before making any transitions.
The below isn't a cure for the cause of problem, but is a means of recovering from and/or avoiding the problem of missing Companions until such time as OEI can get a handle on fixing things.
Thanks to Kianne for this post in the General Discussion Forum...
Diasapperaing Companions
Quote: Posted 10/15/07 12:47 (GMT) by Kianne
Just a suggestion, but I think it could help to have a sticky regarding the disappearing companions bug. It seems like every day there's another 3 posts per forum regarding this issue. I don't know if people would notice a sticky any more than these numerous posts, but it definitely appears as though a lot of people are getting hit with this problem since patch 1.10.
For those that don't know, since at least patch 1.06, summoning familiars/animal companions can cause NPCs (such as Khelgar, Neeshka, etc.) to vanish completely from the party upon an area transition. They are no longer found in the dialog boxes that ask you who you want in your party, and they are basically missing from the game forever. Furthermore, this breaks cut scenes that require those characters (such as Khelgar in the Rite of Tyr).
There are two known ways to fix this problem once it occurs:
1) Revert back to a save made before the problem happened.
2) Some people have claimed that replacing the "ROS" file of the missing companion will fix the problem. I cannot personally vouch for this, but here's how it is done: On Windows, saved games are by default under My Documents\\Neverwinter Nights 2\\Saves\\. The ROS files are named something like "ROS-khelgar.ros" depending on the companion in question. Find such a file with the name of the missing companion from a saved game where the companion is functioning normally, and copy it into the troubled save game directory (overwrite an existing file if any). Make a backup first. I do not know if this procedure has any side effects, but people on these boards have claimed it has restored their companions.
To prevent this bug from occurring, do the following:
1) Go into the Behaviors tab of all spellcasting companions (Wizards, Druids, Rangers, etc.) and turn OFF the "Use Ability" option. Do this for your main character too, if your PC is a class that has such a summon. Otherwise, as soon as you switch to a companion to give him a command or something, your PC will summon his familiar.
2) Do not summon familiars/animal companions manually.
3) If someone has summoned his familiar or animal companion, switch to the character who owns the familiar/animal, hold down the right mouse button on the familiar/animal (either its portrait or in the game world should work), and select "Unsummon" from the right-click menu. (In theory, you could play with familiars out until you need to switch areas, then unsummon them right before the transition... but I wouldn't recommend it.)
Note 1: This bug was not introduced in patch 1.10 but it was exacerbated by the patch because in 1.10 companions on AI now auto-summon familiars/animals.