Guild Wars 2 Halloween 2012 Mad Memoires Part 1

Head on into Lion's Arch. It is now all done up for the first festival season of the year. Head just to the North from the Gate hub and talk with Magister Tassi:
Magister Tassi: “It's an energy smorgasbord out here. The Priory has been mobilized since the word 'boo.' With Halloween on our doorstep, Kyrta is positively rife with spectral spottings.”
Hero: “I'd love to help out. Tell me how.”
Tassi: “Phantom-tastic! Ha, right. So, our sholars were on the verge of a miraculous find: the actual biography written by the mad King himself! Unfortunately, there were several key details left out.”
Hero: “That is exciting. What do you plan to do?”
Tassi: “We've co-opted a bit of archived tech that scans for very old energy. With our upgrades, the device now scans four categories of 'oldness': water, gas, solids, and ether.”
Hero: “So I use this scanner to find bits of his life story and report back?”
Tassi: “Indeed! Let me toss you a bird with more information and your very own scanner. We're missing 6 key moments from the Mad King's life. Report back when you've found them all!”
Hero: “This is going to be fun.”

You will receive the letter, “Your Very own Candy-Powered Matter Meter”. It explains that the Matter Meter is powered on Candy Corn, an elusive material closely linked to the Mad King. When you receive it, unpack it from the letter to get the Meter itself and a Personalized Trick or Treat bag. Unpack the bag to get 6 Candy Corns.

You can find more Candy Cone wandering Tyria. It can show up as something you can mine while exploring. Just find it and take whatever pick you have to it. It is scattered throughout the area. It can also be received through Trick or Treat bags that children will sell in some cities.

Follow the instructions and you will reveal the spirit Serene using the Etheric Field Scan right next to Tassi.
Serene: “I was trying to calm my poor Snow when she reared up and kicked me. I remember falling, pain, and Os. He was hiding above the hay loft, and he was grinning.”
Hero: “Who is Os?”
Serene: “Oswald Thorn, the king's son. His brother, Ewan, is so nice … and cute. My best friend, Lyrica, and I have a crush on Ewan.”
Hero: “Who are you?”
Serene: “I'm Serene of the noble Brody family of Kryta, and I'm twelve years old – forever. I return whenever the spirit of Halloween is strong. It is good to see everything again.”
Hero: “What happened with the horse?”
Serene: “My sweet mare went mad. Os loved to prank, and he'd been feeding hot peppers to animals to watch them suffer. When I tried to calm her, she trampled me dead. It wasn't her fault.”
Hero: “Thanks. I'll make a record of your story.”

This will give you the item: Mad Memoires I: Boyhood: “In which his Royal Madness, yet a boy, discovers the joys of humor.”
It has 2 hints for you:
Site 1 – Dig deep in muck, where all the garbage of Lion Arch flows.
Site 5 – Find Provernic, where the first king's bones rot in the hills.