I have not seen this yet, so here goes: Up to this quest, the game has been stable for me and I can play for hours without much more than a little frame stutter here and there. I have the GOTY version installed to Program Files [i know, it should be in Games], the latest unofficial patch and some MODS installed. I use FOMM and have updated to Microsoft Visual C++2008. My system is XP Pro, SP3, 2GM Memory and NVidia GForce 7900GTX. I had stopped the first part of this quest with a quicksave at the entrance to the pipes for the "drain the intake pipes" part in the Waters of Life quest. So, this is where I load from. After I enter the pipes and complete the task and re-enter the Memorial, the game CTD with a F5 save attempt or an esc to save attempt. It also crashes when I activate the ladder at the evacuation point to head on out to the Citadel after I have escorted Dr. Li and the team through the tunnels. So far I have played this part of the quest through to the ladder three times and the game play is OK. I just cannot save or leave without a CTD. I think it is possible to basically set the game to a point where this part of the quest is completed with a console command like player.setstage... I think someone had a problem with clearing out the mutants and someone recommended a particular setsatge command. Any help with would be appreciated.