1. Talk to Death and accept the quest. Once it begins, as per your request, he will talk to you about Rasial, kind of. He will begin by telling you about vessels and will suggest speaking with Rasial's previous apprentice, Necrovarus, just outside Port Phasmatys.
   
   
   
   
2. The fastest way to Port Phasmatys is via the Ectophial, the Canifis lodestone, or using a boss portal attuned to Araxxi. Ensure you have you have your Ghostspeak amulet equipped if necessary and speak to Necrovarus, located near Ectofuntus. While he will not be pleased to see you, but will be taken back that you need his help. In return for his help he will give you a task of eliminating some Tortured soul that are around the Ectofuntus and limiting his full power potential. He will hand you a Soul urn and tell you 5 Tortured soul will be sufficient.
   
   
   
   
3. Equip your Necromancy gear and kill 5 Tortured soul. Note that you can technically change styles or get help if absolutely needed, however, you must be the first one to hit the monster (successful damage or not) and you must do at least half (1,500) of the damage for it to count. Once you have all 5 souls, the Urn will clamp shut.
   
   
   
   
4. Head back into the Ectofuntus and click it to use the 'Worship' option; this will use your Bucket of slime. This will release the Souls to peace and complete the task he has given you. Once done, speak with Necrovarus.
   
   
   
   
5. Necrovarus will be pleased with the additional power gained from your task and will tell you more about Rasial. After a fair bit of dialog, he will mention a ritual to empower your vessel. Unfortunately, he has forgotten how to conduct the ritual as it has been too many years since he last did it. As such, he will need you to acquire the book of Haricanto from Netty.
   
   
   
   
6. Head to Netty's home, just East of the Slayer Tower. Once you arrive, you will notice a pile of letters by the door. Investigate them and you will go through the pile until you see a letter signed by 'V' whom you believe is Velorina back in Port Phasmatys.
   
   
   
   
7. Make your way over to Port Phasmatys and speak with Velorina in the house North of the Pub. She will inform you of sad news that Netty had passed to the Underworld, ironically while picking nettles for her tea.
   
   
   
   
8. Fastest methods to travel to Um are via the lodestone or the Tome of Um.
   Once there, you can speak with Ted to discover her location OR head straight to the Pub where she is hanging out in the North East corner. Speak with Netty and, after some dialog, she will agree to help you. She will then give you her Death certificate and will so that you can retrieve the book.
   
   
   
   
9. Head to the Port Phasmatys bank and Right click any banker to speak with them. They will confirm the authenticity of the documents and give you a key, as per her will.
   
   
   
   
10. Return to Netty's house and attempt to open the chest in the Eastern room. As per her mentioning, Netty's Skeleton will spawn. If you Right click and talk to the skeleton, it will tell you how it is sad about its life and mention wanting a skeleton friend. Alternatively, you can skip the chat and attack it. Either way, if you use the Conjure Skeleton warrior ability, the skeleton will flee and allow you to unlock the chest and retrieve the book.
    
    
    
    
11. Ensure that you have an Empty bucket and return to the Ectofuntus to speak with Necrovarus. He will tell you to gather a Powerful bucket of slime from the Ectofuntus. Use the Empty bucket on the Ectofuntus then head to the City of Um Ritual Site.
    
    Note: The fastest way to the Ritual site is the City of Um teleport Incantation (level 24 Necromancy), Use the Tome of Um 2 teleport, or Use the lodestone and run West over the Bridge.
    
    
    
    
12. Speak with Necrovarus, who is South East of the Ritual platform, and he will tell you to get the ritual started. Head to the Pedestal and select "Empower vessel" ritual to place the Bucket of powerful slime as the focus. You will need 2 Elemental I (3 Basic ghostly ink each), 1 Change I (2 Basic ghostly ink and 2 Regular ghostly ink), and 1 Commune I (4 Basic ghostly ink) glyphs. Once complete, a cutscene will occur where you will be speaking to Necrovarus when Rasial will show up. He will threaten Necrovarus and force him to teleport away. Rasial will then turn his attention to you, basically saying you are advancing too slowly, but he reveals some information we didn't know before.
    
    
    
    
13. Return to Death and discuss what just transpired to wrap everything up.
    
    

With completion of the quest, Netty's house will now be empty unless you notify her next of kin. Make your way to the shipwreck North West of Port Phasmatys and climb the ladder. Head through the door to the East and talk to the Old Man. You will tell him about Netty passing on to the Underworld. This will complete the "Legal Entitlement" Achievement, which is a requirement for obtaining the Master Quest Cape.

Note that if you need to speak with Netty for anything, like enchanting a Broom for example, speaking with her son (the Old Man) in her house will work instead.