Firestar walked in StarClan's hunting grounds. He tasted the air, and recognized mouse scent. He followed the scent, and followed it up to some brambles, where the scent abruptly vanished.
"Hmmm," Firestar murmured to himself, "Now where could that mouse have gone?"
He started forward, into the brambles. Except, there were no brambles. Firestar looked around and gasped. The brambles were part of an illusion. It must have been put there to hide this place from StarClan. Everywhere he looked, there were bones. It was an area of death. There was one cave in the side of a hollow, and multiple ledges around the hollow walls.
"What could have done this?" he murmured, and leaped down using ledges into the main hollow.
As if on cue, a large black mass lumbered out of the cave. Firestar hissed. The creature looked straight at him and charged. Firestar turned tail and ran for his life. He sprung up onto a high ledge, and sat there, confident that the creature could not get him. The creature, seeing that Firestar was on a high ledge, lumbered away. Firestar relaxed, assuming the creature was giving up. He was wrong. The creature picked up a bone and hurled it with deadly precision toward Firestar. Firestar leaped and the bone missed him by a hair. Then he leaped to the top and ran, fearful that the creature would be able to somehow reach the top.
As he left, he heard a voice. That voice said, "Beware, Firestar. Do not meddle in my affairs again or there shall be dire consequences."
Firestar pelted through the illusion, and out toward the camp. He arrived there, panting and exhausted. Bluestar, Whitestorm, and Redtail noticed him when he was coming in. Once he stopped, and got some fresh-kill to regain his strength, they came over, and Bluestar asked, "Is something the matter, Firestar?"
"Yes," Firestar replied, and described all that he had just seen. None of them had heard of anything like it.
"We must consult all of StarClan about this," Bluestar decided, and went to ask Thunder, the original leader of ThunderClan, to call a Gathering.
After listening for a bit, Thunder decided to go to the other camps with Firestar to ask to call a Gathering.
They decided first to go to WindClan. Wind listened for a bit and agreed to come to the Gathering.
She said, "I will come with you to RiverClan, to show that we have agreed to this Gathering."
They crossed the border to RiverClan, and made their way to the RiverClan camp. River was a little warier, but agreed to hold a Gathering. He decided to come with them because they needed to decide on a time.
When they reached the ShadowClan camp, Shadow was wary, but that was her nature and they were able to convince her after a little while.
Wind, realizing that they had to decide on a time, said, "We should hold this Gathering two nights from now, on the crescent moon."
They all agreed to meet that night, but Firestar was hesitant on waiting a few nights. He was sure something catastrophic would happen.