(Assuming Vasha goes to bed at some point.)

And so each one of you slink off to bed, some of you weary of Fortune, others dreaming of cold, hard coin, and one of you hears the melodic sound of an organ playing a familiar tune. 

Suddenly you all hear a shout! Groggy and fumbling, some of you stumble or peek out into the hallway to find Boss' door wide open as 5 hooded men parkour their way down the stairs and out of sight. One of them appears to be carrying a heavy object wrapped in cloth. You have a single guess as to what it could be - the schema!

What do you do?

Vasha dashes off down the hall! 

Option 1:

If Vasha manages to get close to a runner before making a turn, she will leap forth and drive a fist into the floorboards, creating a great clap of thunder and rocking every beam and board. The shockwave (hopefully) knocks at least 1 burglar off their feet and into the upcoming corner. (Thunderwave: CON save DC13 vs. 7 Thunder dmg, knocked prone on fail)

Option 2:

As Vasha goves chase, it's apparent that she isn't going to catch them. Taking aim at the closest he can see, she unleashes a pair of twirling, multicolored bolts followed by a torent of flaming spears at the rear-most one.

(Chaos Bolt, Twinned, followed by Scorching Ray, Quickened:)

Chaos 1: 7 for 1+6+6 Force damage

Chaos 2: 16 for 5+7+2 Force damage

Scorching Rays: 17 for 7 // 18 for 8 // 17 for 4 fire dmg

Wild Magic Surge?? 15

Tides of Chaos for that 1st botched Chaos Bolt: Re-rolled attack: 25. Another Wild Magic Surge??? 16

(So Vasha kinda fizzled out here. Let's just say she was in a half-comatose stupor and was hazily firing off magic in pursuit ;P)

(Cap is down at the bar, not in bed! Would he have noticed the thieves slink in?)

@Cap - Nope! Unless you investigate, you aren't sure how or where they came from.

@Vasha - They were already down the stairs by the time you got moving. Option 2 it is.

Vasha's chaotic magic erupts from her fingertips, yet most of her efforts grasp at no one! However, her rays of fire manage to severely scorches one of the guys at the back of the group. 

Everyone hears Boss call out from his office, "T-They have the schema! Don't let them get away - !"

Will everyone give chase? 

As they dash down the stairs, Cap will attempt to intercept them, drawing his rapier and attempting to skewer one, and making an attack of opportunity if one tries to slip by him.

Attack: 10 Damage: 4 plus Sneak Attack: 4 if no other thief is within 5 ft. of that one(doubtful)

AoO: 23 Damage: 10 plus Sneak Attack: 11 if the above conditions are met(doubtful)

Cap then pursues the thieves, dashing after them(cunning action)

Copper’s massive blade appears in his hands before he is even fully out of his bed, the commotion drawing anger as he wakes. “WHAT THE **** IS ALL THE RACK-“ his words turn into an angry snarl as he sees the thieves fleeing the scene. His limbs grow longer and his face extends into a partial snout as he bounds after them, swinging with his spectral axe.

Bonus: Shift

Action: Greataxe (rolling in discord)

Olen, wakes at all the noises, seeing his friends running after some unknowns.

Olen comes fully awake at the cries of the schema being stolen. He grabs his gear and runs out in pursuit.

If Olen cannot get within at least 80ft of the enemy using his 30ft of movement:

Bonus Action: Cunning Action - Dash - for an extra 30ft of movement

else if Olen can get within 30ft of the enemy with only his base movement of 30ft:

Bonus Action: Master of Tactics - Help - to give advantage to someone else's next attack again the enemy
"You think you have the real schema? Ha! fools, I have it here, yours is the decoy!"

If Olen is within 80ft of an enemy after any of the above, he will attack:

Action: Attack with Shortbow - Attack: 18 - Damage: 6 piercing damage.

(Ohh I know who could use that Help ;) )

Together, you've managed to fell the cloaked figure in the back of the trope, but the others continue dashing away. 

Outside, the group of them continue running. Shroud manages to get a shot off at the one currently at the tail end of the group. At this point, it isn't clear which of them has this schema. You all know where they are heading - they are running toward a skycoach waiting station! They are only 30 ft from the nearest one.

What do you do?

Distances:
Cap to enemies - 40 ft
Everyone else to enemies - 60 ft

Enemies remaining 4/5

Copper continues running, like a predator chasing prey. Somehow the hefty weapon in his hands doesn't seem to slow him down at all, and he manages to catch up quickly. As he gets close to them, a wickedly fanged grin splits his snout and a burst of greenish smoke erupts from the axe, trailing behind him.

Action: Dash 70 ft.

Bonus: Wrathful Smite

Reaction (if they provoke it): Axe attack, rolling in discord

Kinnik wakes with a jolt to the sound of the scuffle inside. In a burst of newfound insight, he dashes around the exterior of the second storey rooftop to watch for signs of trouble.

Assuming the thieves make it out the door, he casts puppet upon anyone holding an obvious bag of loot and attempts to march them straight back into the Lotus! 

DC 12 CON save, Ru!

Should that fail, he directs Zeph to follow the thieves from overhead. He'll make chase as she does, keeping a safe distance behind.

Olen, closes to within 30ft of the enemy group.

Seeing that the group of enemies is about to slip from their fingers, Olen tried to determine which one of them has the schema:

Action: Investigation check to determine who has the schema: 12

If Olen successfully determine which one of them has the schema, he will:

Bonus Action: Master of Tactics - Help - to give advantage to someone else's next attack, against the enemy with the schema.
"You there, with the schema, you dropped your coin purse!"

Olen would then inform his friends,
"That one there, don't let that one get on the skycoach!"

If Olen cannot determine which of the enemies has the schema, he will:

"I cannot work out which one has the schema, can any of you see it? We must stop them getting on the skycoach!"

Bonus Action: Master of Tactics - Help - to give advantage to someone else's next attack, again the enemy leading their group
"You there, you seem to have dropped your coin purse!"

Cap dashes after the enemies(bonus), stabbing at the one next to Copper. If the one he stabs tries to escape, he slashes at it with his reaction.

Attack: 7 Damage: 9 plus Sneak Attack: 7

AoO: 15 Damage: 4 plus Sneak Attack: 8

It's unclear which of the four remaining guys has the schema. Kinnik isn't able to determine which of them as the schema either, and so sends Zeph out to glide overhead. Copper catches up just enough to slash threateningly at the guy in front of him. With his slash, he manages to see a green emblem on the back of this particular guy's shirt! Cap, unfortunately, misses with all his attacks. (I rolled the advantage for Cap thanks to Shroud's Help, but it didn't pan out)

(Copper and Cap roll Religion!) DC 10 lets you read the spoiler. 

These guys turn a corner out of view. Out of breath, you follow them and reach the street where the switching station is. The thieves have somehow managed to get far ahead of you as you see them boarding the skycoach a good 70 ft away from you. The magic users in your group think one of them might be a mage of sorts themselves. Unfortunately, because of this, you are too far to reach them in time. When you get to the switching station, the skycoach is sixty feet away from the dock, flying away and slowly increasing in speed. 

Seeing your disturbed faces, the clerk at the station informs you that the next skycoach arrives in twenty minutes, but if you’re willing to pay extra, he has four rentable soarsleds and one small skyraft. They cost 1 gold coin per hour each.

Information - 

A skyraft can seat 2 people.
A soarsled can have 1 person on it. Think of it like a hoverboard.

I'm going to have us actually roll and post in initiative order for this flying chase! (Assuming you don't just give up now...?)

Cap fires off a shot from his shortbow at the escaping thieves: 13 Damage: 4.

Religion: 8

If Cap makes the roll, he conveys the info to the others.

(Would Cap's glider be able to keep up with the flying devices, and if not, would he be able to hitch a ride on one, hanging on and using his glider, without significantly slowing it down?)

Olen waves his friends to him quickly. Crowding together, Olen whispers a plan.

"Right, I will go up to the ticket station, to pay for the skyraft and 3 of the soarsleds."

"While I am distracting them, you lot slip passed and get on the soarsleds and skyraft, leave a space on the skyraft for me, and then I will make a break for it and we can get after the skycoach."

"I don't know about you, but I don't have enough coins to my name, not until we get paid and can sell our antiques."

Olen indicates for his friends to shield him from view, as he transforms his appearance a little.

He keeps his cloths the same, and stays a half-elf, but he adds another 10 years to his appearance (making him look in his 30's), changing his hair to dark brown instead of black, and changing his eye colour and nose shape a bit. lastly he adds a scare under his left eye, running horizontally across his cheek, about and inch long.

"Right, that should make me different enough to not be identified, but not different enough from before, that I couldn't have been the same person seen from further away."

"As soon as I start distracting the clerk, you lot get moving, when you are ready, Kinnik, you can still make noises right, could you make some sound to indicate I should run to you?"

Olen, separates from his friends and walks over to the ticket station. He gives the clerk a broad smile as he approaches.

"Hello, so you where saying you have soarsleds and a skyraft for hire?"

Olen will talk details, and try to haggle price, and otherwise distract the clerk, while his friends make to get on the sleds.

Anyone trying to steal the sleds or raft will need to roll stealth to do so! You all figure you can figure out how to ride one or you have already driven one of these things before. (aka, don't worry about your knowledge of how such magi-tech works!)

Sneakety-Sneak: 13

Kinnik looks abashed at Olen's question. He brightens as a thought occurs to him, though. He casts minor illusion and a shrill whistle sounds from nowhere in particular.

The Kenku flashes an OK sign and winks.

Copper is already about to run ahead when Olen starts giving out directions. he stops just long enough to listen, then darts off running low along the ground almost on all fours, with the axe held out next to him. Thanks to the distraction and Copper's speed, the man completely misses the bounding shifter as he runs past, hops on a soarsled and takes off after the  enemies.