I know where they are, I went to them with no companion but I could only give them potions
Did you defeat the lich? Did you complete the quest and talk to the town apothecary (the npc with the black plague mask)? Mmmmm
I'm not actually sure if I properly started the quest for the lich before beating it, I got it from the board but I think I forgot to talk to the apothecary before beating it