Behind the book shelf there’s a long dark hallway, with old wooden floors. Some of which are not fully bolted to the floor. As well as pictures lining the walls. All of people no one seems to recognize but the eyes seem to follow you. 

Jean gets out from behind the book case. "Um guys, I think I've found what we're looking for," and he gestures toward the hallway.

“Doesn’t look very inviting does it.” Stefan peers into the darkness looking for something that might work as a source of light. “Did anyone happen to bring a flashlight?”

"Wow" Gwendolyn peers down the dark corridor, then Stefan breaks her out of her reverie, and she heads back to the table, grabs a spoon and casts light on it.  The entire spoon casts a lovely glow that has about 20 foot radius and dim light beyond that.  She looks at Stefan,  "Something like this?" and uses the lighted spoon to start walking down the now lit hallway.

As she goes, she keeps her eyes peeled and tries to keep a look out for anything, perception: 19

Jean follows along behind Gwendolyn. His pupils expand in the dark, consuming his eyes entirely as he takes in his surroundings. He nervously eyes the long shadows cast by Gwendolyn's light. He was used to the dark though. Growing up, his parents had always kept the lights off to save electricity. They didn't need it much anyway, thanks to their hypersensitive eyes.

Perception: 3 

Gwendolyn notices that there's a noise coming from beneath the floor boards.

OOC: Didn't expect that!

Gwendolyn immediately stops in her tracks - "Guys!  There is something below the floor boards! Do you hear it?"  

Jean stops mid-step and strains his ears.

There's low rumbling noise and what sounds like water.

“That seems ominous.” Stefan takes a nervous step back letting the others take the lead. 

As Gwen stands still on the floorboards over what seems to be water, she investigates the floor to gather as much information as possible.

Investigation: 11

Todd joins the team in the hidden hallway. His PKE meter out and actively Detecting Magic as they move. (I assume it hasn't been 10 minutes since they found the key?) "Ah this is fun I wonder where it goes!" He will carefully creep down the corridor looking for any clues amongst the floor boards wall as they travel, specifically looking to see if the passage looks like it was used recently. He will stay toward the front of the group. 

Investigation: 19

(It has not been more then ten minutes, correct.)

both Gwen and Todd can heard water, but it’s clear that there isn’t much of it. Possibly a fountain, or a small river underneath, and there’s a clear echo. 

"Watch your step," Jean whispers. "I don't know how sturdy this floor is." Even as he speaks, he nearly trips on a loose floorboard.

“Wait a second Jean, any of you have a crowbar on you? Some of these floorboards are loose.”

Todd hears the request for the crowbar and heads over to see what the others are doing. "You think there is something underneath here?" He sets his duffle bag down and starts rooting through. "Ah here it is!" He pulls out a large metal crowbar. "I thought I packed one. Not really sure why... but hey glad I have it. I bet one of you guys are stronger than me but I would be happy to help".

(You’ll have to roll strength for it.)

I will help someone else who might be stronger, they can have advantage on the roll with my help action.

(Jean has a -1. Did we all dump strength? Haha)

(Too funny, and here I was waiting for you since I'm a squishy gnome wizard!)

"Here, give it to me" She says exasperatedly. She gets down on her knees and tries for the closest loose floorboard.

Strength w/advantage: 11 3

(Did I just waste two crits?!?  I have +0 to strength!!)