There are a few things not mentioned above that people might like to know:
1) After doing the mission you can use the box in front of the portal to get more Vessels to turn into Ambrosias. You get 20 at a time (turns into 100 Ambrosias) and on handing the Ambrosias in to the box you get 1 Sliver per Ambrosia. You can repeat until you run out of metal.
2) In front of the portal are 6 barrels with lights on. These are lighting up in turn probably according to participation or time.
3) Members and GM’s can currently claim 10 Black bullion, 21 Black Marks of Venice, 5 Extant Third Age Fragments and 1 8 hour 100% xp potion from the Item Store. These are claimable ONCE PER ACCOUNT.
Atm that’s the only known way to get Fragments.

The next mission in The Whispering Tide event is called “Enter the Filth” and is available from a Custodian who’s now appeared by the filthy portal. It has a half hour cooldown and rewards one Extant Third Age Fragment. The first mission and repeatable hand in is no longer available. This isn’t a solo mission so if you get stuck, want to help people or just for fun you can group up.

A walkthrough follows so if you don’t want spoilers then read no further!

Enter the Filth Walkthrough.

Having grabbed the mission from the Custodian you enter the filthy portal.

You now find yourself in a filthy portion of Agartha with no options on where to go.

You’ll proceed down the pathways fighting your way through groups of filthy humans and single filth mobs, nothing taxing. The darker filth patches all over the pathway will debuff you so they’re worth avoiding.

At the end of the first pathway is a platform with a blocked archway on the far side. Once you get onto the platform mobs will drop from the sky and a small event begins. Although I’ve not had problems with this I’ve heard it described as the hardest part of the mission. When the first drop of mobs are killed there will be several more waves of filthy humans. Once the last of the last wave is dead the archway is unblocked and you may continue.

N.B. If you snag on something invisible as you go under the archway then jump and you’ll get past it. This applies to all archways which you unblock as you progress.

After some more jogging and more trash you’ll come to a second platform with a second blocked portal. As you go onto the platform a large mob called the Titan of Dis emerges from the filth puddle in the middle of the platform. The Titan uses two smallish AoE’s as well as an aerial mob dropping larger AoE’s. The fight just consists of moving out of AoE’s and not standing in goo. Once he’s dead you may carry on.

Another keep fit session and trash bash later you come to the final platform. The mob emerging from the goo this time is called “She Who Walks Outside”, she’s one of the large four legged spider type mobs found in the Issue 6 Egypt missions. She uses a frontal cone AoE and the aerial mob drops more large AoE’s and some of the filth seems to expand as the fight continues. As with the Titan this fight is just a case of avoiding AoE’s and not standing in goo. Once she’s dead head through the archway, grab some Lore on your way and head out of Filthy Agartha to finish.

The second phase (going through the portal) is now complete and we seem to be in a pause before anything else happens.