Speak to Ava in Draynor Manor, and offer to help her improve her living conditions. She asks you to get her a few undead chickens at the farm near Port Phasmatys. Travel there and speak with Alice, and select the option "I'm here about a quest."
Alice tells you she has not been able to speak with her husband, who tends the animals, since he died. Her husband asks you to tell Alice that he still loves her, and that if you talk to her he will consider selling you some of his chickens. Return the message to Alice, who asks you to find out where he put the farm's cash stash. Alice's husband will tell you that he put it in the bank, like she always told him to. Alice asks for his bank pass, but her husband refuses to give out his pass numbers (after all, you might be a scammer).
You suggest to Alice that by giving her husband an altered Amulet of Ghostspeak, he could tell her his bank code directly. She suggests visiting a witch who lives west of Fenkenstrain Castle. Travel to the Old Crone's house and speak to her with the Amulet of Ghostspeak unequipped. Ask her about the farmers to the east, and she will agree to help out, creating a Crone-made amulet in your inventory.
Chickens and Magnets
Take the amulet to Alice's husband (remember to re-equip your Amulet of Ghostspeak) and speak with him again, and he will attempt to catch an undead chicken in a cutscene, with eventual success.
He agrees to sell the chickens to you for 10 ecto-tokens each. Take these to Ava, and she will tell you that in order to construct your reward, she will need a magnet, and send you to the witch that lives next door to her for help. The witch asks you to bring her 5 iron bars, which she will trade for Selected iron. She instructs you to hit it with a hammer while standing in the Rimmington Mine and facing north.
Travel to the mine and use your hammer on the Selected iron. Remember, you MUST be facing north or it will not work. It does not matter where you stand in the mine, provided you are within the mine and facing north. It will turn the Selected iron into a Bar magnet.
Take the magnet back to Ava, who will take it and tell you more about her plan. You will gain 50 crafting experience, and she will tell you that your next task is to chop down one of the attacking trees of Draynor Manor.
Look for an Undead Tree in the yard in Draynor Manor, and try to chop it.
You get a message saying that the hatchet was ineffective. Speak with Ava again, who recommends you speak with the slayer master Turael in Taverley, or to his daughter, Spria.
Travel to Burthorpe and speak with Turael or Spria. If you have a Games Necklace, you can get there quickly by using the Burthorpe Troll Invasion option. Select the option "I'm here about a quest." Turael will offer to make you a Blessed hatchet, which can chop down Undead Trees, if you bring him a Mithril hatchet and a Holy Symbol of Saradomin. Trade him the items for the hatchet, then head back to Draynor Manor to chop some Undead twigs from one of the Undead Trees.
Putting it all Together
Take the twigs to Ava, who now needs to decide on a container to hold everything in. Speak with her again and she will give you her research notes to translate. To translate the notes, select and de-select pages until you have this:
Speak with Ava again, who tells you that all you need to do is make the container using hard leather and polished buttons (which can be obtained by pickpocketing H.A.M members). She will give you A pattern.
The H.A.M hideout can be found between Draynor and Lumbridge, if you did not previously get the buttons:
Pick the lock on the trapdoor and pickpocket H.A.M members until you get Buttons, then polish them to get Polished buttons. Use them on the hard leather to create A container, which you will need to take back to Ava.
Take A container back to Ava, who will give you your reward: her newest invention, Ava's attractor.
If your ranged level is high enough, she will automatically give you the upgraded version of her invention, Ava's accumulator.