Let's see if I've been paying attention.  You're going to make yourselves invisible and cast teleportation circle to get back to the nearest safe spot.  Gregor is doing a few things to make scrying easier.  That about right? 

(OOC: Yes, I don't know what others are thinking but that's exactly what Gregor wants.)

(OOC: yup)

(ooc: doooo iiit :)

(OOC: No objections here)

So Zane drops the silence and casts teleportation circle.

Verbal components and a casting time of one minute.  Oh dear. 

Make a Sleight of Hand check using your spellcasting ability. 

11 not proficient in it.

Burk wakes up, glances over at you, shakes his head, rolls over, and goes back to sleep.  His dire wolf curls up at his feet and watches you. 

After 4 rounds of uninterrupted spellcasting, 1 ogre and 1 dire wolf burst through the door, take one look at you, and attack.  Roll initiative. 

Ogre initiative: 8

Dire wolf initiative: 12

Zane initiative: 21

(Gregor Initiative Roll: 8)

Gregor acts before the ogre. 

Aurora Initiative: 11

Ketrey initiative : 19

"everybody protect Zane, He must complete the spell" she says as she notices the intruders

Initiative order:
Zane (21)
Ketrey (19)
Dire wolf 1 (12)
Aurora (11)
Gregor (8)
Ogre 1 (8)

Zane uses his action to continue casting teleportation circle (5/10 rounds). 

Ketrey's turn. 

Ketrey approaches the ogre and attacks before he can alert anyone further to their presence. 18 to hit inflict wounds at 5th level

30 necrotic damage if it hits

You miss.  Not only do you miss, but you also fumble the casting.  Make a Wisdom saving throw against your cleric spell save DC. 

9 versus DC14

(OOC:OMG.FML)

Apparently, you are not meant to harm that ogre. 

You are cursed.  While cursed in this way, you cannot attack that particular ogre or force it to make a saving throw.  You also cannot target it with or include it in the area of a spell or other ability that requires neither an attack roll nor a saving throw, like sleep.  You can repeat the saving throw whenever you finish a long rest, ending the curse on a success. 

It's the dire wolf's turn.  The ogre barks something in Giant and the dire wolf leaps at Gregor and tries to bite him.  18

Somehow, I knew it would be a crit.  Gregor takes 18 piercing damage and must make a DC 13 Strength saving throw, being knocked prone on a failure. 

(Strength Save for Gregor - 19)