The Toa Metru had returned to Metru Nui, and found it barren, shaken, and crawling with spider-like Visorak, named in legend as 'stealers of life.'
Injected with Visorak venom, they became Toa Hordika, half Toa, half Rahi. They met the Rahaga, dimunitive creatures with wisdom beyond their years. Now, the Toa Hordika, along with the Rahaga, have begun the search for the mythical rahi Keetongu, whose power of countering venoms may be the Hordika's only chance to become Toa again.

Nuju and Kualus stood in front of a Knowledge Tower in Ko-Metru. When the great earthquake occured, this particular tower had split in half, causing it to resemble a Y.
"Is this the place?" Nuju asked his Rahaga friend.
"Yes," Kualus replied. "This is the largest ice bat nest in the city. The perfect place to learn the language of flying Rahi. Come on now, we haven't got all day."
Nuju was about to follow Kualus when he heard an odd sound. It sounded like a muffled cry coming from below him.
"Kualus, look!" Nuju exclaimed. "I think I found an injured Rahi!"

Just as Kualus turned his head, Nuju was thrown up into the air by an explosion underneath his feet.
After readying his Rhotuka, Nuju looked down into the pit that had been concealed by the rubble. Then he let out an audible gasp, for curled up inside the pit was something that should not have been there.
A Matoran.

The Matoran opened his eyes. "Water..." he croaked.
Nuju motioned to Kualus, who took out a canteen of water from their raid of a Le-Metru storehouse and gave it to the parched Matoran.
After the Matoran drank the water, he stared at the sky. He was engulfed in a blast of bright light, and then a Toa stood there.

Nuju jumped back. "Krahka," he exclaimed, "How on Mata Nui did you escape the Kahgarak's darkness field?"
The Toa, (whose body, Nuju noticed, was crystalline) replied, "What Krahka? All I remember was the quake and a strange dream. In it was..."
"That's not important," Kualus cut in. "The important thing is that you are a Toa. You are not supposed to exist. There are only six Toa on Metru Nui."

The stranger bent his head. "And if I am not supposed to exist, how could I have placed my Toa Stone in a slot in the Great Suva?"
Suddenly, Nuju realized something. There were seven slots in the Great Suva that day we became Toa...
"Come," Kualus said to the Toa. "Come with us. We must talk."
And so the two of them walked off, with Nuju cautiously following behind.

Soon, the three companions reached the Tower of Toa, the Toa Hordika's headquarters. The crystalline Toa gazed in wonder at the tall structure, but had little time to marvel at this sight when Kualus abruptly knocked on the door.
A part of the steel door slid open and an orange eye peeked out. "Name and business," the voice grunted.
"Nuju and Kualus," the Toa of Ice replied cooly, "We have, uh, important news."
The door swung open, and Matau Hordika stepped inside. "Good to see you again, Nuju," the former Toa of Air exclaimed, "How did that raid go?"
"The raid went successfully," Kualus said, "We found enough supplies to last us for a week, and something else as well."
The two pushed the crystalline Toa inside.

There were cries of "Sweet Mata Nui!" and "How...?"
Vakama Hordika stared at the Toa and asked, "Who are you? And what is your power?"
The Toa sighed. "My name is Hikan, and I control Crystal. Crystal can come in many different shapes and sizes, and that is the basis of my power. I can zap creatures with my staff and then transform into them."
"A useful power," murmured Nokama Hordika. "But you do not have your staff here. How can we utilize this ability if you don't have your tool for doing so?"
"Actually, he CAN use his power," said a voice by the door.
All heads looked towards Nuju, the speaker. "I lagged behind on our walk to our tower, and I found this." He held out a purple claw-topped silver staff crackling with electricity.
"My staff!" Hikan exclaimed. "Erm, if you Rahaga could step outside for a second..."
"Of course!" Kualus replied and lead the other Rahaga outside.

Onewa Hordika frowned. "Why did you do that?" he asked curiously.
Hikan sighed. "I have something to tell you that wasn't fit for their ears. During the time I was trapped under all that rubble, I kept on having the same dream, over and over. I saw, in my mind, a large orange Rahi--"
"Keetongu," breathed Whenua Hordika. "The only hope for us to be Toa Metru again."
"Along with this Rahi, I saw a single word: Impostor. Now that you told me that Keetongu has a cure of some sort, I saw the connection."

"Keetongu does not know how to cure venoms. He may even be working for the dark side. I'm sorry to say this, but...

Keetongu is an impostor."