Jay was completely silent while following the tracks. Who could blame him? He had lost the golden nun chucks to the enemy. Who knew what Lord Garmadon's skeletons could do with them, or worse Lord Garmadon himself!

Jay had never felt so much guilt. The entire world could be in danger. Maybe the entire universe! And it was all his fault.

Jay's only consolation was that his friends were going to help him make up for his mistake. With their support he'd know he'd set things right or die trying. Jay just hoped it was the first of those two.

"It looks like the tracks are headed down this mine. I sense they are using this mine to create another entrance to the underworld," said Zane as the tracks disappeared into one of the caves.

"We'll have to close down their operation before leaving with the nun chucks," said Cole.

Jay nodded in agreement and was about to go in when Cole blocked him with his scythe.

"You're never as quiet as you have been for the last half hour," he said looking squarely into Jay's eyes, "What's wrong?"

"Sorry," said Jay, "I just feel really bad about what happened."

"You'd better," said Kai, "I don't care if they finally got your silly little invention to work. You shouldn't have taken the nun chucks."

"I was planning on working on a portable energy source next, but for now I…" Jay mumbled.

"You should have thought of that before you made your wings powered up!" Kai declared in Jay's face.

"Cool it Kai!" said Cole, "Jay's already upset. You don't need to make this worse for him."

"I don't think 'upset' is enough," said Kai angrily, but he said no more to Jay.

Jay sighed as the four entered the cave. It was dark, but the ninjas were used to moving around in dim light. The mine began to slope downwards steeply making it tricky for the four to keep their footing. At the bottom of the decline the path split into two.

"There are fresh prints heading in both directions," said Zane, "but I cannot sense which group carried the golden nun chucks."

"Is something blocking your powers?" Cole asked sounding concerned.

"No, it's just that both sides are showing joy at bringing the nun chucks to Lord Garmadon. It has made it impossible to specify." Zane explained.

"What do we do from here?" Jay asked.

"We'll have to split up. Kai, Jay, you two take the right tunnel. Zane and I will take the left tunnel. We'll meet up back here." Cole said.

Jay didn't like the idea of being alone with Kai right now. Kai was too angry at him. But Jay felt that given this was his fault anyway, he had no room to argue. do Jay simply nodded.

The tunnel before them proved to be much like the area behind them: dark, sloping, and full of skeleton tracks. Jay followed them through the winding cavern for what felt like hours.

Finally, Kai asked, "Are you sure this is the right way?"

"No idea," Jay admitted, "I'm just doing what Cole told me to do."

"So you'll obey Cole but not Sensei?" Kai accused.

Jay couldn't hold his feelings back any longer. He turned facing Kai directly in the eyes.

"I GET IT, OKAY?" he shouted, "I WAS IRRESPONSIBLE WITH THE GOLDEN NUN CHUCKS. I SHOULDN'T HAVE USED THEM TO POWER UP MY INVENTION. BUT AT LEAST I'M TRYING TO SET THINGS RIGHT! ALL YOU'VE DONE THIS ENTIRE TRIP IS RUB MY BAD ACTIONS IN MY FACE! AND LET ME FILL YOU IN ON SOMETHING, BUDDY. IT'S NOT HELPING! IT'S…"

"Look out!" Kai said, suddenly pushing Jay to the ground and lying on top of him.

THUNK!

An arrow embedded itself into the wall.

Jay saw that if Kai hadn't acted when he did the arrow would have gone right through his head.