Nate kneeled by the masks and looked at his journal and then back at the masks. There were four masks on the ground and his drawing from the Peabody Museum showed four images, he felt like there was a connection here that he was missing.

"What are these masks for?" he murmured to himself, "Why are they here?"

He shone his torch around the cavern, they must serve some sort of purpose. It was when his light, and Mia's - who was examining the door - cross paths that they saw it.

"What's that?" she asked, approaching it, Nate trailing behind.

Embedded in the wall was what looked like a hook that seemed to run deeper into the stone wall.

"It looks like a hook" he replied probing it with his finger. The hook was the size of his little finger and made from a softwood. It jutted out from the wall, with the opening facing towards the roof.

"Look, there are three others" Mia said.

Following the light from her torch, he saw that there were similar hooks, two on each side. "What do you think they are for?"

And then it made sense, "It's for the masks!"

"What?"

He returned to the masks on the floor, spreading them out so that they lay next to each other then he showed Mia the picture of the underside of the toppled statue with the pictures of the Sun, Spear, Octopus and Leaf,

"Don't you see, it's a way to unlock the door" he said excitedly. "These masks represent the four Gods right?"

"Yes."

He pointed to the images in his journal, "And do these images represent the Gods as well? The spear could be Ku, the God of War right?"

While she seemed sceptical Mia agreed that it could be correct.

Nate's excitement grew, "Then it's simple. We just place the masks on the hooks in the order as they appeared on the base of the statue."

"Wait a minute, Nate" Mia said holding her hand up. "How do you know that those images correspond to these masks?"

"It makes sense, doesn't it? All the clues from the base of the statues lead us to this point, they have to be related. Just call it intuition."

"Intuition...right. And what if we are wrong?"

"Maybe nothing, maybe we lock the doors forever, or it might spring a trap."

"That seems rather risky for something based on intuition."

Nate gave her a big smile, "Just trust me" he said and knelt in front of the masks. He picked up a mask depicting a snarling face with a headdress that flowed down either side of its face, "This one is Ku, right? It looks like the one above the door."

He placed that one aside and indicated the other three, "Who are these masks meant to represent?" he asked.

Mia knelt beside him and picked up a mask. This one wore a similar snarling expression with a five-prong headdress that made it look like a hedgehog.

"This one is likely Kāne. He was the creator and was considered to be the ancestor of the people."

Nate showed her the journal and she pointed to the sun, "That's Kāne, he was also the sun God."

Taking the mask from her, Nate approached the first hook and just as he raised it, he turned to her and said, "You might want to stand aside."

Gathering the other three masks, Mia moved as far to the side as she could. Despite the cold and darkness and being entirely unconvinced this would work, she felt her heart racing as she watched him carefully place the mask on the hook. He held it there for a moment as if he were hanging a picture and wanted to make sure the hook would hold before he slowly removed his hands.

Nothing happened. The sound of water lapping against the steps behind them was the only sound in the cavern.

And then there was a loud thunk, like the turning of a deadbolt, and the mask slowly lowered a couple of centimetres. She waited, breath held, waiting for the cavern to collapse in, or the tides to rise, but there was only the sound of water and darkness.

"I guess that was the right one" Nate chuckled.

Unsure of whether she was relieved or angry at his gung-ho attitude, Mia returned with the three remaining masks and she examined one. This mask had the same menacing expression and wore a tall, narrow headdress that reminded Nate of a mitre hat.

"That's Lono" Mia said.

"How do you know?"

She looked at the last mask, this one had a similar headdress but was more rounded and the face had the same menacing snarl but with finger-like protrusions around the bottom half of the face. "Because this is Kanaloa. These are tentacles and Kanaloa symbolised by an Octopus."

Looking at the book, he said, "So Kanaloa will be the first one on the right and Lono next to it?"

"That's right."

Nate took the masks from her, "You're sure?"

"What happened to intuition?" she mocked but nodded that she was sure and he approached the two hooks on the right. First placing the mask of Kanaloa and then the Lono mask on the hooks the deadbolt sound followed soon after. He picked up the last mask, the one of Kū, and handed it to her, "Last one," he said. "You do the honours."

She took the mask from him and ran her hand over it, her fingers probing the crevices and hollows. The mask was wet with centuries of damp covering it but the wood was still solid, like it was carved only yesterday, Approaching the final hook, she let out a shuddering breath, her nerves were on edge and she almost dropped the mask. This was an entirely new experience for her, usually she spent most of her days researching in a cramped office sharing desks with other researchers and museum employees. And now...

She placed the mask on the hook.