The beam of cold energy strikes the lock, but it does not break. Evidently temperature-based magic is not particularly effective against an unliving object such as this.

I'm frustrated... but I don't have a lot of other options. If it looks like it did any damage at all, I'll cast it again to try and bust that blasted lock. Hopefully, it's resistant to cold damage instead of immune...

Attack: 16 Damage: 8

When that almost certainly fails, I peer through the lock or under the door, trying to get a look at whoever is inside.

"Braxton," I hiss loudly. "Open the door now... it's only a matter of time before I get in. You could save us both a lot of trouble; I'm not here to kill you. I have a message to deliver."

(Oh, I didn't catch that you cast it at second level. Let me roll the save.)

The man actually isn't running at all! He's staring at Chlorys with a dreamy smile on his face, the only one here who looks like he thinks everything is fine. A few other people begin crowding toward the door after it slams shut, opening it and beginning to run.

To say that she wasn't absolutely horrified would make Chlorys a liar and seeing a flying skull seemingly materialize out of nowhere and crush a table with its maw was horrifying. The voice that reverberated throughout the wooden ship had Chlorys covering her ears; she grimaced. Chlorys put her face in her hand, dragging the skin downward in frustration. "I said I wanted exciting and this is what I get." Grumbling, she hastily makes her way towards Camus, hoping that Von can handle the main floor. She wanders into the kitchen, snatching food from a counter in front of two bewildered looking workers. Climbing steps that she assumed lead to the office of Braxton she finds Camus standing in front of a door. 

Camus looks up from the lock, and Chlorys gets to see his actual face for the first time. It takes Camus a split-second to remember that he took his mask off...

"Oh, crap," he mutters, quickly throwing his mask on over the cracked skull.

"Alright, let's get in there and say hello to Mr. Braxton, then get out," I say. "I'm afraid that I'm not much good at picking locks... I could blast through this lock, given enough time, but I think that you'll probably be able to get us in a lot faster."

I produce my dagger and small knife and hand them to her.

"I'm not sure if these will be make great lock picks, but they should be better than trying to pick it with your fingers."

I'll use the Help action to try to give her advantage on the Lock Picks check... presumably, by holding things in place for her and/or using cantrips to help jostle the lock's mechanics.

Chlorys, you head up the stairs after seeing this massive glowing skull, and as Camus turn, you see behind his mask for the very first time... and you see that very skull. Two empty sockets, gazing soullessly into your eyes. Bare, teeth grin at you, yellow-brown from age. An empty hole where his nose ought to be lets you see into his hollow skull, where your darkvision pierces the shadows, allowing you to see the back of his cracked skulls. Some of aged flesh still cling to the skull, baked onto it by time, staining the bone. Then, it begins to speak. Camus is not dead. However, he is most definitely not alive.

from the cover of the hallway im going to use thramaturgy to have spiritual weapon skull continue threatening patrons with maritime doom until they all leave, then have it hover up against the door for anyone who tries to enter. 

The patrons don't waste any time in fleeing from the skull, out into the night.

An icy cold feeling of dread washed over Chlorys, Camus had turned to her as she ascended the final step; he had removed the mask that had kept his appearance a mystery, at last revelaing his true face, or what happened to be left of it at least. Empty, glaring eye sockets met Chlorys' startled golden gaze. A wide toothy grin, yellowed and stained with age permanently etched upon his face.  Bits of decayed flesh still clung to the skip. Goosebumps spread across her her flesh and all the hairs on the back of her neck stood up the moment Camus had faced her. "I.... um.... wha?" she stumbles over her words, nearly falling backwards down the stairs in shock. Camus quickly conceals his face once more, but the image of his skull was still burned fresh into her mind.  With a trembling hand she nods, taking the dagger and small knife from Camus, intending to pick the lock

(Should I make a sleight of hand check, or just a dexterity check?)

(Dexterity(Thieves Tools) check, with disadvantage due to not having proper tools)

Alright, as stated earlier I'll use the Help action to aid her in any way I can.

 14

As Chlorys struggles with the lock, Camus is starting to worry... a lot. This isn't looking good.

"Let me make this clear, Braxton," I say loudly. "we're going to get in sooner or later, the only variable is how pissed we'll be when we do it. Open the door NOW!"

I shoot another Ray of Frost at the lock to emphasize my point...

Attack: 22 Damage: 10

The lock is relatively simple, and Chlorys is pretty confident that she can open it without much struggle... the only problem is, there's a significant amount of frost gumming up the mechanisms, preventing it from moving properly. The lock stays closed.

"Hey V... uh, War-orc... we might need your help on this damned door!" I yell down the stairs, carefully avoiding using Von's name... sure, everyone's seen us, but it's probably best not to make it too easy to track us all down. "Toss a couple tables and chairs in the way of the front door, then get up here!"

Suddenly, another idea occurs to me... the lock clearly isn't budging with the ice... but the wooden door might be vulnerable to something else I have.

I attempt to rot out the wood (that is to say, attack with Necrotic damage) by casting Inflict Wounds using my free casting from the Shadow Touched feat.

Attack: 15 Damage: 14

Just to make sure I actually hit the blasted door, I expend my use of Bless from Von.

1

Evidently, this sort of damage is far more effective. The wood begins to twist and shrink before your eyes (eye sockets) and soon the rot which covers it causes several of the boards to fall away into a stinking heap of deflating wood. Behind the hole in the wood caused by Camus' spell there is a comfortable-looking office... which is completely empty. The only sign of any former inhabitance is the door leading out onto the ship's deck, which hangs open. Braxton has evidently elected to run.

I curse, but it's it's clear that our guy is scared, just like our employer wanted... I bash some of the loose boards out of the way with my staff to make a hole big enough to enter the office. Since we're upstairs, and there was nothing around back, the only place he has to run is if he jumps into the sea. I look out onto the deck, readying my action to cast Hold Person if I see him.

Roll Perception!

21

Damn you, dice...

I call Chlorys to come help me with this.

Sorry, when I edited the comment it changed the dice roll... the original result was 8 (but I'm happy to take the 15 if we say Chlorys followed close behind to use the Help action).