After I talked to Lassan in the basement, he said he would meet me upstairs. As I started to head that way, he appeared at the base of the stairs and attacked me. After killing him, his body did not appear in the coffin, and I am unable to proceed. Can anyone think of a workaround for this game stopper bug? I tried using the cheat to create Lassan but that didn't work, and I tried spawning Bodhi, but she seems invincable in the "spawned" version. Plz help! Thanks.

Quickclay out.

He should have re-appeared in the spiked circular room, not the stairs, so try there. After killing him, he should retire to the middle coffin in the room with the three coffins. After staking him, Bohdi appears.

Which coffin do you mean exactly? I first killed all the other vampires and then checked out for a secret passage, it is left of the chamber where you first meet Lassal.
When you have killed Lassal, he will go to his coffin. You go there too and put a stake through him. Then Bodhi should appear and you will have to fight her.

Thanks for the replies! The coffin I was referring to was in fact the bottom one in the room with the three vampires you can stake. I think the bug is that when I killed Lassan, it was in the wrong place and he body never returned to his coffin to be staked. Right now there is 2 out of the three vamps staked, and no option to stake the third one (Lassan) because his is dead and doesn't appear anywhere else, so Bodhi won't appear in the room she is supposed to. Any ideas?

Try killing him again, except upstairs. CLUAConsole:CreateCreature("LASSAL02").