The prince grabbed her hand, holding her back when he saw she was about to enter the sunken stairway.

"Please, we need to hurry," she said.

"You do not know what's in there," he said.

A piercing sound came from everywhere at once, and both Ella and Prince Ilathor put their hands to their ears. When the volume ebbed Ella shook the prince's restraining hand away and rushed headlong down the stairs, barely cognizant of her surroundings as she ran down the corridor and started to climb the spiralling stairs at the other end.

It would have taken Killian some time to swim to the Sentinel. Had he made it here in time to keep the relic out of the Primate's hands? Had he met Evrin, and were they now fighting the Primate together?

What would she find at the end of these stairs?

"Slow down!" the prince cried from behind her.

Ella didn't bother to reply. Looking up, she saw blue light above her. Feeling her heart race and her stomach clench with fear and dread, she ran up the last few steps.

Then she was out.

It took Ella a moment to take stock of the scene in front of her. The cavernous chamber curved high above where the Sentinel's shoulders and head must be. She was probably at the level of its waist, and where she stood there was a crescent-shaped gallery with tiered steps facing an expansive pool. Ella instantly knew the liquid was essence.

At the far end of the gallery an old man — Evrin — lay prone in the corner. Nearby stood a tall warrior in the garb of an Akari, staring, as Evrin was, at the pool. Ella realised that not far away from her Miro held an arrow pointed at the Akari, but his eyes were also on the pool.

They were all staring at Killian. Ella could see that the protection of the runes she had drawn on his skin had faded. His body looked bruised and battered.

"It must be stopped," Evrin said, his voice wheezing. "Now that it has activated, it can only be stopped from the other side. The seals must be replaced, but they won't work if the beacon isn't stopped."

Prince Ilathor stepped forward, trying to shield Ella, but she fought him as he tried to hold her back.

Everyone else stared at the relic.

The tall oval mirror floating above the platform in the centre of the pool slowly changed hue, from gold to red.

Killian looked back at Ella, and his expression said everything. She didn't know what the relic was, but her intuition told her it was some kind of doorway. She didn't know what lay on the other side, but she knew Killian, and she knew from his face that he was a man preparing to die.