Garren is starting to get annoyed at this lack of progress, so he says: "We are stuck, it seems. Let us go out and have the children come in, at the very least, and explain the route to their parents and younger sibling, as well as the monster".

Rod

"mmmmm....mmmm.... maybe...they will be more accurate, giving us a description on the route we have to follow for the basement?? mmmmm....moreover...I guess we already check outside if there are any other entrance directly to the basement right?...maybe something hidden? Maybe is something hidden we should check for....." 

The Warlock will exit with Garren to fetch the children if possible, in any case, he will search the house garden and walls for any hidden passage to the basement...

((Investigation: 10))

 You go out, after being a while in the house, trying to find any trace of the children. But when you exit you're only greeted with fog that envelops the entire house like a solid wall, not allowing you to see further than 30 feet. The children are gone.

In the garden there are no basement entrances, or at least yo can't find any.

Just to clarify, in case I wasn't clear enough, the stairs continue further up on the second floor. 

"The only way to the heavens is up." Simon says, quoting an ancient proverb. Tossing another scrap of dried meat to the dog he begins the ascent. On instinct he pulls out the book featuring his name, feeling the familiar chill trickle down his spine. He flips it to the most recent page.

(No, you made it clear, TheVinter, we just assumed that basement should be down, haha)

“Are we going upstairs, then?” Reshi looks confusingly at Simon. After gaining some reassurance that he understood correctly, he continues, “If you don’t mind, I would like to look for the boy, since he is supposed to be on that floor.”
Reshi walks to the stairs, and once they have all regrouped, nods to everyone and he continues quietly up the stairs.

Stealth: 10
Perception: 13 - (passive is 11)

Edit: Reshi walks upstairs not so quietly, I guess.

Simon will cast Mage Hand and follow.

Stealth: 8

Simon tosses some food at the dog and then checks his book once more, and he (unsurprisingly at this point) finds the last ten minutes of his life written on the pages that once were blank. Done that he decides to follow Reshi upstairs.

The red marble staircase delivers you to its full height: the third floor. The air is choked with dust. The walls— carved with autumn woodland scenes—are mounted by unlit oil lamps. An infant's cries cut the silence into tattered chunks while a cobwebbed suit of armor stands in eternal vigilance, facing the balcony railing. Facing you

"A child," Simon whispers. He begins to creep towards the source of the noise. 

Stealth: 12 

Rod

"A child? yeah....probably, I start losing credit on what we are seeing and hearing here......" The Warlock reluctantly follows Simon

Reshi slowly follows after Simon and Rod. On the way he would like to inspect the suit of armor.

Investigation: 16

Garren follows the group and looks over his surroundings,  highly suspicious of everything around.

Reshi and Simon start slowly moving towards the source of the noise. Reshi and Garren follow them shortly after with Reshi only stopping for a bit to investigate the suit of armor, founding nothing. 

Just as you reach for the door, you pause, craning your ear. The wailing of a newborn echoes throughout the suite. A young woman tries to quiet the child, poorly singing a lullaby. Gently, you tease open the door, finding no one inside. Instead, the cries come from behind a thin door to your right. "Hush little baby," the woman sings, "don't say a word. Mama's gonna buy you a Blinsky toy... And if that toy don't work... Walter, stop crying. Please, stop crying. Morninglord's light, please just stop crying."

Then, you open the door. 

Cobwebs are everywhere in this room: along the windows, between the the posts of the bed, stretched across the wardrobe. Even the mirror set into the wall is draped in the eerie silk. Stained glass doors lead to the balcony you saw from outside, and gloomy, dust-choked air haunts this place like a distant memory. Child's wails come from behind a door to your immediate right.

Simon puts a thin finger to his pale lips and presses his back against the wall to the immediate right of the door. Summoning a mage hand, he mentally orders it to push open the door.

Rod

The Warlock looks at Simon and whispers "Yess...shhhhh.....shhhhh you know guys what is funny about you? it seems like......WE are listening...voices..." He has a weird grin upon his face...."This is going to be interesting..." Rod starts rummaging throw his Book while waiting for the Mage Hand to do its job....maybe...he will find something new written on his Book,  "Yesssss, we could find something....eheheheh..."

Reshi waits silently for Simon to open the door, while glancing over his shoulder to make sure there is nothing and no one behind them.
Perception: 11

You approach the wails of the baby's room, pushing open the door. His dreary nursery is decorated in strange toys—a mobile of black and white bats, a rocking chair in the shape of a wolf. A black shroud embroidered in windmills covers the crib. No woman can be found—perhaps she left for the balcony—but still the baby cries from his crib.

Simon shivers but recollects himself. "I fear nothing but death." He whispers, striding towards the crib purposefully .

Garren feels immensely uneasy, but refuses to back down, following Simon closely.

Reshi stays in the cobweb covered room and takes another look around.
(Does it look like people live here despite the state of the place? Or does it look completely abandoned?)
Perception: 20

“This doesn’t make sense.” Reshi mutters to himself. Then he walks towards the other door leading out of the room and opens it slowly. (from the master bedroom to the balcony)

Rod

Rod walks slowly after Garren and Simon towards the crib, holding his Rod with both hands