Starting Laid to Rest
To start Laid to Rest you have to go to the Highmoon Hall in Morthal and speak to Jarl Idgrod Ravencrone. During the day she sits on her throne opposite the entrance to Highmoon Hall. Ask her “What happened to the burned down house” and you eventually start the quest.
Finding the Burned Down House
Next you have to go to the burned down house which is in the south-western part of Morthal. Follow the walkway along the houses and lake to the end and you will find it. Speak to Helgi’s Ghost. She will ask you to find her when it gets dark. I’m not sure when you start to be able to find her, but I waited until midnight and then went to search for Helgi’s Ghost.
You have to go up the hill behind the burned down house. If you are having trouble with this part I suggest you watch the video below which shows where you have to go at around 1:50 into the video.
Recovering Alva’s Journal
To prove what happened you are asked to recover Alva’s Journal and return it to Jarl Idgrod Ravencrone. Once you reach the house be sure you are hidden and lockpick your way in. Inside Hroggar will attack you be he is easy to kill because he doesn’t wear any armor and has a weak weapon. You can find Alva’s Journal in the basement inside the open coffin. You have to read it in order to continue with the quest.
Killing Movarth Piquine at Movarth’s Liar
Jarl Idgrod Ravencrone will ask you to kill the vampires at Movarth’s lair. Except for Movarth Piquine I found everyone easy to kill, especially because it was easy to sneak kill them. Movarth Piquine is a powerful magician. I hid in cover and used a bow and arrow to kill him. The cover allowed me to avoid the damage he deals easily.