Something's Fishy in the Palace

WIP

This is an investigative quest that will lead the party through two primary locations. It is not meant to be combat heavy unless events are provoked by the group. This adventure can serve as an introduction to Oloxalim Zexzu and the Thieve's Guild. It deals with learning of a plot to poison a feast on the Flying Palace.

Discovering the Plot

There are two main ways to start off the quest. If the party naturally made their way onto the ship / bought tickets, the adventure can start off during their stay. Otherwise, the group can stumble upon the information in any city.

City Rumor Mill

The party can learn of the poisoning plot in a number of ways.

Someone eavesdrops on a private conversation in an alleyway or hidden bar room.

The party finds a note either carelessly discarded or on a Guild member.

They read a column written by a "prophet" who claims something horrible will happen on the ship.

The elite must learn another lesson. Go to the new dead drop and gather the vials of oil. Tickets to the Palace will be attached. Be quick and portal back after tainting the food.

— A note on tan paper signed with a fish shaped stamp.

"Are you sure we're safe talking in here?"
"Yes, but speak quieter damn it. Anyway, we don't have much time. The banquet's in two hours and we gotta spike all those fish still."

— A sketchy conversation.

On the Ship

If the party starts on the Flying Palace, there are a few ways to learn about it there.

Someone hears Guild members discussing their plans through their room walls / connected vents.

They see an odd figure sneaking around places they shouldn't.

The note or an oil vial falls from a Guild member's pocket without them noticing.

Another alternative start.

If the party has already met Oloxalim, this plot can be something they assist with if they wish to pursue that instead. First they'll need to gain his trust before this is available. After hearing his plans the party can either help if they agree with his plight, or go ahead with trying to stop it.

Boarding the Palace

In order to continue investigating, the group will need to either find or purchase tickets to board the airship. There is the potential to earn a trip as a reward for completing any major quests beforehand. This plot can be inserted into the date for the earned vacation. The easiest method is to

purchase tickets directly. They are available through the internet (if the party has access to tablets or other computers). Tickets can also be bought at large stores or at an airship port.

Tickets

100 GP Per person per night
500 GP Per person for a week trip.

No room on the ship!

While trying to acquire tickets, the party learns the ship is sold out during the days around the poisoning. Getting aboard will be tricky, but there are options.
Get the ticket(s) from another guest. The banquet is an annual event with posted attendee lists on their website. Any member will do. The party can either buy the tickets off of them, do the person a favor, or pass a DC 17 charisma check to convince them to hand over the ticket.
Convince the staff to talk to the captain in private before the ship sails. This will be a DC 15 charisma check. Use the found note or any other evidence to prove something might happen.
If the party has access, they can portal / teleport onto the ship the day of the event and work from there. Befriended magic NPCs can help; it would either be a favor or cost the amount of the spell / ability.

Race Against Time

Depending on when the party gets aboard the airship, the time frame to save the guests will vary. This particular voyage is four days long. The banquet is held on the last night at 7 PM and the poison attempt is planned for an hour beforehand. It is best for the group to utilize the full trip to ensure all traces of poison are dealt with.

Finding and Searching the Bedroom

There are only two Guild members on the entire ship. They share a bedroom, but are out "blending in" with guests from 8 AM to 9 PM during the days leading up to the banquet. Unless the party encountered them before, tracking their room can be difficult.
To recall info about the Thieves Guild, a DC 14 history check is needed. Any member with a criminal background or equivalent will pass with a 12 instead. This will reveal the secret symbols members wear. Otherwise, the culprits will be in "normal" clothing.
The members don't do much else to stay hidden. Once identified, the party can take measures to figure out which room is theirs and find a way inside to investigate. Potential options include: pick pocketing their key, lock picking the door ( DC 16 ), crawling through a vent, or utilizing other abilities.
Items to find in the room.

Investigation Checks

DC 12: Thieves tools, basic leather armor, and 1D4 randomized books.
DC 15: A sack with 80GP, 2 potions of greater healing, a randomized trinket, and the case with all the oil vials.
DC 18 Wallets with the member's IDs, an uncommon magic item, a pearl necklace, and 2 bottles of wine.

Locations

Any major city
The Flying Palace

Elite's Feast

Every year during the last month of spring, Omari's richest individuals gather on the Palace to party and indulge in a banquet. They utilize it as a PR stunt. Supposedly 50% of the profits from that night are given to charities. Oloxalim doesn't believe this charade at all.

Fish Poison

The substance used to tamper the food is Gorbo Oil. It's pale yellow and toxic when consumed. Effects vary depending on the concentration.