Bernard nods, and without a word begins heading back to the attic. He picks up the skeleton corpses of Rose and Thorn and buries them in their rightful crypts. Afterwards, he kneels in front of the crypts and recites a long prayer for the dead- sanctifying their burial and wishing them peace in the afterlife. 

Upon putting the skeletons into their rightful crypts the ghosts leave you. Both are clearly happy, and you hear the sound of playing children, a sound very at odds with this evil place. Clearly the two kids are finally able to move on from this dismal house. You have 2 luck points now. You can use these luck points to replace any roll, after it is made, by expending a luck point. It works exactly as the Lucky feat in all ways.

For the time you spend in the family crypt, you find it the most peaceful place so far in this entire house. Likely you could rest here without danger, and that is not something you would have found possible anywhere else in this miserable house.

Bernard smiles, glad that the ghosts of the children are finally at rest. Perhaps he did well by coming to this house. He rests only for a minute or two before he looks to the door as his gaze becomes more serious. 

"There is a monster in this basement..."

He stands up and casts a Protection from Evil and Good on himself. Then, he exits the crypt and continues onward to the common room. 

A wooden table and four chairs stand at the east end of this room. To the west are four alcoves containing moldy straw pallets.

A door is set in the North wall and a passage leads East from this chamber.

A quick scan of this room tells you there is nothing here of interest though, so you have to decide if you wish to check out the northern door or the eastern tunnel.

(I assume the east passage was to the hallway intersection from before?)

The northern door stood forebodingly ahead of him. Bernard turns to Lancelot, who's still hanging in his pack, and ruffles his fur. 

"Just a little farther, little boy. Then we'll be out of here."

He puts his ear up to the door, listening for sounds instead. Then, he will enter. 

No, the South passage would lead you back to the intersection of the attik stairs and the passage leading further South to the Crypts. There is an East passage here leading further into the dungeons, as well as the North door leading somewhere as well.

Hearing nothing at the door you open it. Inside you find...

A 4-foot-diameter well shaft with a 3-foot-high stone lip descends 30 feet to a water-filled cistern. A wooden bucket hangs from a rope-and-pulley mechanism bolted to the crossbeams above the well.

Five side rooms once served as quarters for senior cultists. Each contains a wood-framed bed with a moldy straw mattress and a wooden chest to hold personal belongings. Each chest is secured with a rusty iron padlock that can be picked with thieves’ tools and a successful DC 15 Dexterity check.

Bernard did not have the capabilities to loot the chests, nor did he feel inclined to take whatever vile trinkets they held. He instead leaves this room and heads to the east passage that leads further into the dungeons. 

Down the Eastern passage you find...

This room contains a plain wooden table flanked by long benches. Moldy humanoid bones lie strewn on the dirt floor around the table. As you study one of the human bones you notice bite marks along the bone, as if someone had eaten from it and tossed it on the floor near the table.

In the middle of the south wall is a darkened alcove. With how observant you are, you notice a soft noise from inside that darkened recess.

A passage continues out the East side of this chamber, the sound of chanting still filling the air of the dungeon you plod through.

Bernard becomes immediately alert once he sees the gnawed bone. It may be something that he's seen before. Immediately, he begins moving quietly up to the alcove, hoping to get a jump on whatever is inside the darkened recess. 

Stealth: 19

(Disadvantage) 22

Monster initiative: 15
Bernard's initiative is 5 (rolle din game log.)

Moving up to the alcove you glance inside...

What seemed for a moment like a protuberant band of stone wriggles and slithers. What must be its head opens hook-tipped tentacles like a flower to reveal a beak as big as a smith’s pinching tongs. The whole of its body is somewhere between squid, snake, and slug, its pebbly skin rippling to drive it forward with surprising speed.

Multiattack. The grick makes one attack with its tentacles. If that attack hits, the grick can make one beak attack against the same target.
Tentacles. Melee Weapon Attack: 7 to hit, reach 5 ft., one target. Hit: 10 slashing damage.
Beak. Melee Weapon Attack: 16 to hit, reach 5 ft., one target. Hit: 8 piercing damage.

You are up.

(Would it have been possible for Bernard to use his Warding Flare against the tentacle attack, giving it disadvantage?) 

(In any case, assuming the first attack does hit, Concentration check on Protection from Evil and Good: 11)

The thing in the alcove bursts at Bernard with frightful speed. He shakes off the attack and retaliates. 

Bonus Action: Cast Spiritual Weapon

Attack: 25 Damage: 9

Action: Cast Toll the Dead. WIS Save 15 or 19 damage if wounded from the spiritual weapon, 8 if not. 

(Yes warding flare would be allowed here. You are not surprised so you do have your reaction.)

Disadvantage roll for attack: 8 Take the lesser of this and the 22 from the previous post.

The spiritual weapon you summon strikes true, driving deep into the creature's worm-like body. Then you sound the bell of doom, and it attempts to resist the sound... Wis save: 5

The creature is barely standing, but standing, or slithering, it is. It lashes out again with those tentacles...

Multiattack. The grick makes one attack with its tentacles. If that attack hits, the grick can make one beak attack against the same target.
Tentacles. Melee Weapon Attack: 20 to hit, reach 5 ft., one target. Hit: 7 slashing damage. Beak. Melee Weapon Attack: 12 to hit, reach 5 ft., one target. Hit: 7 piercing damage.
You are up again.

The slithering creature's foul appendage barely misses Bernard as a burst of light deflects its attack. 

Unfortunately, it strikes again and true this time, causing Bernard to stumble back a bit. 

Concentration: 9

Bernard loses concentration on Protection from Evil and Good. 

Action: Toll the Dead, WIS Save 15 or 12 damage 

Bonus Action: 

Spiritual Weapon Attack: 22 Damage: 12

It is hard to tell if it was the bell or the spiritual weapon, but the worm thing fell limp to the floor, unmoving.

Combat is over.

The dank alcove has nothing of interest in it, just more gnawed bones. Moving back to the main chamber you walk aorund the table, noticing more of the gastly signs of the eating of human flesh. The tunnel, across from the one you entered this chamber through, seems to be the only way forward though.

The cruel monstrosity lay dead at his feet, yet the chanting did not stop. Bernard frowns. 

"Is this not the monster the children were speaking of?"

It was just too easy. There had to be more ahead. 

The old exorcist mediates and revives the shield of Protection from Evil and Good around him before continuing on through the tunnel. 

Moving on to the East you come to an intersection...

The ghostly chanting heard throughout the dungeon is noticeably louder to the East. Looking down that passage you see a stairway that descends further.

To the North you sense an overpowering stench of death and decay. That passage runs a short distance then opens up into a chamber.

To the South you see another passage that runs a short distance before opening up into a chamber.

Which way do you go?

Bernard stalwartly continues forward to the northern chamber, holding his glowing holy amulet before him. 

As you head North you notice dirt falling from the side passages, and hear the sound of scratching, which eventually resolves into a fist breaking through the dirt wall of the passage. To your horor four ghouls are clawing their way out of the tunnel walls.

Ghoul initiative: 3
Your initiative: 9