Soren's DC10 CON Save to maintain concentration on Moonbeam after being hit by the Vampire Spawn's claw:  17 (success)

The laceration removes most of the fortification he had received from Bramble the spirit bear what seems like ages (but was less than an hour) ago.

Who is this Tatyana that the abomination is looking for, Soren wonders.  Is it another name for Ireena, who we know Strahd seeks?

Aloud he merely grunts with pain, then growls, "this little songbird has a little flock behind him, cursed thrall of the darklord, unholy in Silvanus' eyes."

With his eyes he looks at the non-combatant serving women, making a motion with his eyes for them to flee by any other exit.

( Burr trusts in Soren, and he is deeply conflicted by 'abandoning' the two women with Viktor and whatever is moving about upstairs.....he takes the stairs)

Burr, confident that Soren has the Vampire Spawn well in hand, makes for the stairs.  As he dashes past the lone, blood covered guard, the man gives a gasping cry and pokes out at the warrior with his spear.

Spear:  18  Piercing Damage:  4

The man then cowers behind his shield as Burr passes.

At the upper landing, he can hear the sound of commotion from the middle of the second floor.  A man's voice booms out, "Rah!  WHERE IS SHE!"  From his vantage, Burr can make out another guard up here.  He looks almost as scared as the man on the stairs, though perhaps a little more in control of his faculties, and his gaze is fixed on someone or something further down the hall....

Giles steps in and sees Soren facing one of the vampire spawn, he has less confidence in his ability to tackle the undead fiend alone, so he steps forward into the hall 10 feet or so, holding up his coin to the vampire, saying “Back, away you foul thing!  Leave this place and seek your grave!”  He points his hand and another bolt of radiant light shoots down onto the beast.  He follows with his telekinetic mage hand, hopefully pushing him away from Soren.  

Sacred flame to the Vampire Spawn facing Soren : DC 14 Dex save or take 8 points of radiant damage.  

Bonus action : Telekinetic mage hand shove : DC 14 strength save or be pushed 5 feet back from Soren.  

[This is still round 1, which saw Giles climb down from the window.  That would have exhausted his movement, (15' of climbing from the window) but he would still have an action and bonus action, so the ranged attack and shove can still work this round, but Giles is stuck outside for now.]

DEX:  12

STR:   7

Dancing light from Giles' spell falls upon the vampire, burning it with holy light.  As it tries to bat away the intangible energy, it is caught off guard by Giles' 'shove' and is pushed back 5' away from Soren.

Zefla is still up!

Zefla is shocked at the amount of carnage she sees in front of her.  This whole place was made of nightmares.  She is about to attack the creature next to Soren when she hears the man's voice raging above.  Instead, she dashes up the stairs after Burr, to the man on the stairs, "Just close your eyes." she tells him as she runs past.

She used her BA to dash, if she sees the man that is an enemy, she'll fire her bow at him.

Attack: 10 - but with the crazed situation around her, she misses.

Downstairs:

The serving women in the dining room, whether picking up on Soren's cue to leave or acting on their own initiative, slip out through a side door into another downstairs room once the Vampire Spawn is busy out in the hallway.

Beside him on the lawn, Giles hears the sound of someone dropping in beside him, turning to see Ireena.  "I'm sorry to ignore your counsel, Father.  But you weren't there, at St. Andrals.  All those people... this monster and I have unfinished business."  She draws her longsword.

In front of Soren, the Vampire Spawn snarls and runs a tongue over 3-inch fangs.  It looks only slightly singed by his and Giles' magics, and for the moment Soren stands alone before it.  Across the hall, the snarling becomes even more savage behind a closed door.

Upstairs:

Heavy boots stomp in the corridor before a someone familiar figure comes into view.  "Where is she?!" shouts the man you recognize as Izek Strazni, captain of the Baron's guards and, until moments ago, Ireena's captor.  He is tall enough that his bald head threatens to catch the beams above the hall, and his fur-collared cloak is smeared with blood.  He holds a broadaxe in his left hand, while you spot the familiar deformity of his right hand... it is demonic in appearance, the flesh discolored and the fingers ending in claws instead of nails.

Another guard steps into view behind him, looking as terrified of his commander as he is of the snarls and screams coming from downstairs.

They all stop short when they see Burr and Zefla running down the upstairs hall towards them.  Izek's eyes narrow.  They are dull and bloodshot.  "Who... what are you doing here?  Have you taken her?  WHERE IS MY SISTER?!" he bellows, hefting his axe.

Round Two:  

1. Soren
2. Vampire Spawn
3. Burr, Zefla, Giles
4. Izek and Guards and ???
5. Ireena

Soren is taken aback when first Burr then Zefla run up the stairs instead of assisting in the fight with the Vampire Spawn right in front of him.

"When the pack is challenged to hunt dangerous and threatening prey, it is unwise to split the pack to look for other dangerous prey to fight at the same time."  The druid attempts to cant his voice just loud enough to carry up the stairs to his otherwise occupied companions, but no further.

Like a retreating animal, Soren locks his eyes on the undead abomination that Giles had Telekinetically shoved away as he retreats thirty feet east, going from 10' away from the Vampire Spawn to 40' away, out the door.  He hopes the apparently bewitched guard on the stairway does not spear him.

Nettle flies in the Vampire Spawn's face once more (help action) and uses Flyby to wing her way out the door back to Soren's shoulder.

Seeing and hearing Ireena outside, Soren's heart sinks.  He very specifically does not look in her direction, though his quiet words are meant for her.  "The darklord's thralls search the night specifically for one named Tatyana.  Do we know who that is?  It would seem unsafe for her, whoever she is, to be out in the open, all the more so if the Baron's monstrous captain Izek, whose voice I hear upstairs, appears rabidly obsessed with her."

And what was that about his sister??  (Soren wonders).

The ten-foot diameter cylinder of pure moonlight (Moonbeam) glides back out into the hallway to cover the Vampire Spawn and the area just north of it, so anything coming from further down the hall would have to pass through it as well, along with the undead creature already within it.

Movement:  Soren trots 30' directly east out the door (now 40' from Vampire Spawn).
Action:  Soren shifts his Moonbeam (5' radius cylinder) over the Vampire Spawn and the area just 5' north of it.  Creatures starting turn or entering AoE:  DC14 CON Save.  15 radiant damage on failure, 7 on success.  Shape-changers make save with disadvantage and revert to original form on failure.
Bonus Action:  none
Free Action:  Soren stows his longbow behind his shoulder.
(Nettle takes help against Vampire Spawn - next attack against it has advantage).

Burr has no idea who Izeks sister is but he knows he heard women crying out for help downstairs and he knows he doesn't want Izek up here where ( he believes) the others are hiding.

" She's downstairs being attacked by devils! Come on!"

Deception/Persuasion-  4

( Not sure he'll have a chance but if that crappy Roll makes Izek think Burr has his sister, Burrs legging it downstairs and charging at the nearest Vamp.)

CON:  17

The Vampire Spawn hisses as Soren's moonlight washes over it again, stinging but not badly harming it.  Soren can see that the burns from the last round of spells have not healed, and the damage seems to be accumulating.  It swats ineffectively at Nettle as the spirit owl buffets it with white wings before flapping away again out of reach.

The undead creature steps forward out of the light as if to pursue Soren outside... but then pauses.  It glances back at the moonlight beam and peers at the shadows of those gathered with Soren outside... and then it steps out of the hall, back into the dining room.  "Perhaps the songbird would like to play the role of cat, instead?  Follow, follow, follow... Catch me if you can..." it rasps as it shuts the hall door behind it, passing out of sight.

Upstairs, the big man freezes at Burr's words.  You can see the indecision wash over his face.  He clearly doesn't believe you, but the fear that you may be speaking the truth is undeniable.

[I'll wait to see what happens with Zefla and Giles before resolving Izek.  Also, Burr still has movement and actions.  Does he wait to see what Izek does?  If so then it would have to be as a Reaction.  Otherwise he can act now.]

1. Soren
2. Vampire Spawn
3. Burr, Zefla, Giles
4. Izek and Guards and ???
5. Ireena

( Burr- Reaction- Dash- Downstairs)

Giles reaches into his pocket and grips his coin tight, mind racing as he puts all of the chess pieces in his mind into position on the board.  He looks upstairs quickly, hearing the unmistakable voice of Izek, stomping toward the stairs.  He sees the foul creature stepping out of the moonbeam and south into the dining room again.  Rather than race forward after him, he turns to Ireena, the new key piece on the table.  He moves to protect the Queen.  

Giles touches his chest, quickly casting guidance and then turns to say to Ireena, very quickly and urgently… “Don’t you see, it is Izek that is the threat, he wants to recapture you and keep you as his plaything!  I know what to do, but you are crucial!  We must keep you safe!  Please, climb back up this rope to safety!  I’ll be right behind you.  Don’t let Izek capture you again!  We will set him to go kill the vampire, let him do that!  Please, I beg of you!!”

Persuasion of Ireena to climb the rope and flee! (with guidance) : 19

After he makes his case, as a free action, Giles sticks his head in the door far enough to shout toward the stairs, “She went into the dining room!  Quick, we have to find her!”  He makes an effort to hide the pitch of his voice, altering it to that of a stranger.  

Movement : climbs up the rope after Ireena (if she hopefully goes up the rope as suggested…)

Zefla catches herself staring at the big man.  He towers over her like none of the other men, and his way... makes it that much more menacing.  Getting control of herself takes a beat, but hearing Burr and Giles, and the fact she doesn't want him to find Ireena up in the hiding room, she takes her cue.

"Your sister?  How is that possible, you aren't her brother, Ismark is!!"

She tries to judge his reaction.. Insight: lol nat 1 for a 3

"C'mon!  The dining room!  We need your help!"  She turns and dashes back down the stairs.

Izek's attention snaps back and forth from Zefla to Burr.  "What?  What do you know about her!?"  When they dash back down the stairs, he races to follow.  "Come back here NOW!"

The guard on the stairs, spurred to reaction by the raging voice of Izek, makes another spear poke at Burr as he passes by...

Spear AOO:  16  Piercing Damage:  6  

Izek reaches the landing, and based on the sound of boots on floorboards, the other two guards are close behind him.  "WHERE IS SHE?!"

Hearing the roar of Izek's voice, Ireena looks willfully at Giles... and then sheathes her sword.  She climbs the rope, with Giles right behind her.  Above, the sound of Tourmaline and Victor arguing can be heard. 

"I know!  I told her not to..." the voice stops short as Victor pokes his head out the window.  

"Oh...  Look, she's climbing back up.  There, it sorted itself out, then."  He steps out of the way to allow Ireena and Giles back inside.

The bestial snarling from behind the other hallway door continues, but from within the voice of a man calls out "Izek!  What's happening out there?"  For the moment, his attention focused on the downstairs hall, Izek ignores the call.  Meanwhile, the sound of movement from the room near the front door ceases abruptly.

[Giles and Ireena are back in the attic room.  Soren and Nettles are outside, while Burr and Zefla are in the main floor hall.  Moonbeam has one more turn left.]

1. Soren
2. Vampire Spawn
3. Burr, Zefla, Giles
4. Izek and Guards and ???
5. Ireena

Soren shakes his head and grits his teeth as he hears Izek descending the stairs.  Just what we need, a rabid direwolf joining the hunt among us wolves, when we know in the end, we must put down the direwolf in turn as well...

He speaks as he moves west once more to the door that the Vampire Spawn had closed behind it:  "The remaining undead abomination turned and retreated behind this dining room door.  It may be setting an ambush, wishing us to chase, yet I feel we must hunt it or it will slay more of the pack."

Nettle flies west (60' movement with Flyby) above him, though near the door, she backs away (north) momentarily.  Finishing his 30' movement west past Zefla, Soren opens the door to the dining room, knowing well that he may be facing a readied attack from the Vampire Spawn.

Assuming the door to the dining room opens, Nettle peers through to try to spot the Vampire Spawn.  If she spots it, she communicates its location to Soren.  If not, she flies through into the dining room to try to spot it and communicate location.  Either way, she takes the dodge action

IF Soren learns the location of the Vampire Spawn one way or the other (being attacked by it or either he or Nettle spotting it), he moves his Moonbeam over it and tells the others where it is.  Otherwise he uses his action to don his wooden shield.

Movement:  30' west (assuming he can get by Zefla since she did not specify her location exactly, and is small-sized anyway).
Free Action:  Soren opens the dining room door
Action:  Soren either moves Moonbeam if Vampire Spawn location is spotted by Nettle or himself, or if not, don shield.  If needed for Moonbeam:  DC14 CON Save if starting turn in or entering AoE, 8 radiant damage on fail, 4 on success.  Shapechangers make save at disadvantage and revert form on fail.
Bonus Action:  none

[The snarling could be a mastiff, though whatever is snarling sounds mad with bestial rage.]

Soren moves down the hall and throws open the dining room door, bracing for an attack that never comes.  

The dining room is empty, the door into the adjoining room still ajar.  

Nettles flies in from outside, down the hall and into the dining room, ready to dodge any attack.  Only at the limit of her range does she spy the Vampire Spawn... all the way across the next room, lurking near another open door.

[Soren can't see through Nettles eyes without using an action (which makes Owl-guided spell targeting a problem) but I think it could mentally communicate roughly what it sees enough for Soren to attempt an accurate movement of the spell.  I'd probably make this a roll to see if Soren gets the distance and position right, but as this is the last round for Moonbeam I will let you have it.]

Soren moves his spell over the creature.  

CON:  8

Its skin blackens and crackles once again, and it hisses in a loan, baneful way.

The Vampire Spawn steps out through the next door, closing it behind itself.  It looks like it is near the rear of the house, in the kitchen near the backdoor.  But now it is once again out of Nettles' sight behind a closed door.

Soren feels the light of his Moonbeam slowly fading.  [Concentration no longer necessary as the spell has run its full duration.]

1. Soren
2. Vampire Spawn
3. Burr, Zefla, Giles
4. Izek and Guards and ???
5. Ireena

Burr gave the guard on the stairs a look that promised future conversation then thundered down the hallway and shoulder charged the door at the end of the hallway heading through into the room beyond.

Action- Dash.

Athletics- 19

(FML)

Giles reaches out of the window and pulls up the rope, doing his best to make sure it is not visible from below.  He holds an action ready to lower the rope in case Soren, Zefla or Burr wish to climb up.  He also keeps his telekinetic mage hand active to shove any vampire that tries to climb the building to the window.  He says quietly and calmly to Victor behind him, “Victor, Izek is down there and a couple of guards, and one of those horrible vampires.  I don’t know if there is anything else you have that could help them.”  He barely leans out the window periodically to look below and see who may be approaching.