Four will enter, only three will leave

So the BKC group continues it's adventures after their last adventure leaving the town of Travin: [link] . After leaving the town at night it began storming, so our adventurers tried finding a place to shelter from the storm. They found a lone inn in the woods, they entered and found a note saying that the owner was away for the moment and would be back later to collect payment if they stayed the night. The only other person in the inn was a female pregnant Dwarf, CC imidiatly started demanding a map of the region out of her. She said she and her husband were new to the region, and he had gone out to investigate the area. Meanwhile Kyrish was taking apart the doorway so he could fit his carriage of books through it. After awhile everyone went to bed, 4 hours later Kyrish woke up, went downstairs and noticed a bloody note stabbed into a wall. It said; "Four will enter, only three will leave", reading this Kyrish tried to leave, but a magic force field was preventing anyone from leaving. Then Blue woke up and came downstairs he found Kyrish, but before they could do much a bunch of Skulks burst out of the kitchen and attack them. As well some ran up stairs and tried attacking CC and the Dwarf. Blue and Kyrish defeated their skulks, then Kyrish convined Blue into killing CC so they may be allowed to leave the inn. CC and the dwarf woke up and started despatching their skulks. Blue ran up and CC accidently shot him, Blue then tried to kill him, luckily CC escaped and fled out onto the patio of the inn which was in the magic wall. Blue, Kyrish, and the Dwarf preceded to enter the kitchen to find where the Skulks came from, CC was hiding in the cabinets. They found a trap door leading to the celler, they went down it, CC sneaking behind. In arrived in a storage room with a tunnel leading on, they were attacking by a bunch of shadow serpents, they fought them off though. They continued on and found a bloody wall saying "Are you in the Lion's den?", continuing on they encountered a bear that had been chained up and fought it. After that came to a fork in the road, Kyrish had been left behind gathering stuff, and CC was sneaking along, the Dwarf and Blue went one way and found an ooze. This ooze though could summon monsters, and preceded to attack our "heros", luckily it was defeated. CC had went down the other side to another fork, went down one side and discovered more crates and a dead man, this had been the owner of the inn. It was around this point that the group started hearing screams from a man, the Dwarf reconginzed it as her husband and ran for him. Everyone minus CC went down the other pathway and came to a big room, at the other end their was a glowing grey cup producing a fog that was rising up and causing the magic field. In front of it was the dead male dwarf, but the screaming was still happening, the party turned around and up and saw the menacing Chelicern; a long-legged spider like creature that could mimic creature's screams. The party attacked and it was a brutal fight, the Chelicern kept puching Blue down, and Kyrish kept casting fear on it. But this is where things get really really good, CC from the shadows was still cross about being targeted by Kyrish to be killed, so he wanted to weaken him. He pulled an arrow and from the darkness shot Kyrish in the leg, unfortunetly it did so much damage that Kyrish was forced to amputate it after the battle. The beast was defeated and the cup destroyed, but wait theres more. The Dwarf was so distraught by her husbands death that she became so weak, this didn't help when she began going into labor. The party tried helping the process along, but were shocked when instead of a baby dwarf, a horrible monster emerged instead. It had a horse-like head, bat wings, horns, clawed hands, hoofs, and a devil tail. It began growing and fled down the tunnel. The group followed, Blue grabbing the Dwarf's axe. When they arrived outside they saw the creature land on the arm of a mysterious cloaked man. The man said "The second herald, your time will come adventurers". With that he disappeared into the shadows and the quest ended.
Note: I do not own D&D or Blue, CC, and Kyrish.