The return of the D&D campaign: This time it's potatoes

[Raid]

If they're set in the floor, it might be possible to fill the mechanism with something like sand or detritus from the surrounding area, jamming them up. If they're electrical in nature rather than purely mechanical, maybe pour water in?

[Mantis]

We can't make any suggestions, we're not there and I wouldn't think to mention them when I message you. ¬_¬

[Raid]

I realised the other day that Charr still had a cantrip to learn, so I picked up Message, though I suppose you mean Slythe doesn't have a way of asking.

[Wrathbone]

In the meantime, I think stealth is probably the way to go rather than continue to brazen it out, so I'm going to attempt to sneaky-sneak over to the overseer's office.

So you were dumped in the bottom-left room at area 8 and the overseer's office is area 2, which means to get there you'd have to get through the portcullis to the right of 4a. There is a guard posted on the outer side of it (i.e. in the vestibule, not in 4a) who unlocked it on your way in and then locked it again. 4a is currently empty but there are a couple of guards playing cards in the room to the north of yours in area 8. You can also get to area 7 where there are apparently people sleeping.

I'll repost the map for convenience:

[Sly Boots]

Is it too late to say that I'd kinda been hoping that out of hours the internal portcullises would be left open?

[Sly Boots]

Hm... this might be slightly unconventional, but could I squeeze through the portcullis grille if I was, for the sake of argument, half the size?

[Mantis]

I'm sure Slythe has this one in the bag and everything is going swimmingly.

Sage decides to give it another thirty minutes and orders a rum from the bar.

[Wrathbone]

Is it too late to say that I'd kinda been hoping that out of hours the internal portcullises would be left open?

Hm... this might be slightly unconventional, but could I squeeze through the portcullis grille if I was, for the sake of argument, half the size?

The gap between the bars is about 4 inches, so it might be a squeeze to say the least.

As a professional rogue, you would have immediately clocked that the guard stands fairly close to the portcullis - i.e. within arm's reach from the other side.

[Sly Boots]

Ok, here's what I'm thinking then. How about sneaking to close to the portcullis, empty the remains of my waterskin/soup concoction into the lever slot (just in case that helps gum up the works).

I've heard Beniago speak, so I could cast minor illusion towards the guard in the anteroom to say, in Beniago's voice, something like "get over here, you dolt, and help me with this". Ideally at a volume where the card-players wouldn't hear it.

Then, still stealthed, I scurry past when it opens. Workable?

[Sly Boots]

Oops, posted before that edit above.

[Sly Boots]

I have a pretty awful Plan B, in the case of the above.

How about I go up to the card players and offer them a tot of my special rum to help pass the night, and use my dragon poison waterskin?

With them out of the way I could grab the portcullis guard from behind, knife to throat, and force him to open it.

Pretty stealthy, right?

[Mantis]

I don't foresee any issues with this plan that may impact our attempts to infiltrate the vaults again over the next couple of days.

[Sly Boots]

On consideration, I think I still prefer my Plan A, as it's less potentially messy. To help me be even sneakier I can cast Reduce on myself, reducing the chance the guard sees me as he comes through the gate.

[Sly Boots]

I don't foresee any issues with this plan that may impact our attempts to infiltrate the vaults again over the next couple of days.

Slythe is suddenly overcome with a strange sensation of sardonic disapproval as if from afar.

[Wrathbone]

On consideration, I think I still prefer my Plan A, as it's less potentially messy. To help me be even sneakier I can cast Reduce on myself, reducing the chance the guard sees me as he comes through the gate.

Okay, so roll a deception check for the impersonation of Beniago and (assuming it's successful) a stealth check for hiding and sneaking through past the guard (I'll say with advantage if you're casting Reduce Person).

Also you're pretty sure you can do the impersonation at a volume where the card players wouldn't hear it.