Sam kept his vigil at Caleb and Scarlet's bedside, crisscrossing the room as he squeezed out a cloth in a bucket of cold water and applied it to Caleb's forehead. Lily did the same for Scarlet.

Sam was beginning to feel more and more anxious that Polly had not returned. She had said that she was stepping out of the room for just a moment, and he'd expected her to be back at least an hour ago. He was finding himself increasingly impatient, and was no longer able to contain his worry for her.

Sitting in this room, watching Caleb and Scarlet so sick, did not help to relieve his anxiety, either.

Nor did the fact that he was still worried about his sister, and longed to be out there, protecting her.

He didn't want to be sitting here, acting as a nurse. He felt that he could be put to better use, and his impatience was building.

He looked up at Lily, who was kneeling on the far side of the bed and applying a cloth to Scarlet's head.

"Can you watch them both for a few minutes?" he asked. "I want to check on Polly."

Lily nodded, looking tired and solemn.

Sam turned and hurried through the room, strutting across the ancient stone, heading for the oak door. As he did, he wondered why he was so concerned for Polly? Indeed, he wondered why he felt such strong feelings for her at all. Whenever he was around her, he felt as if he were caught up in a storm of emotions - happiness, joy, love, jealousy, anger, sadness... He had a hard time admitting to himself that he cared for her. But he was beginning to recognize that that was obvious.

Was he falling for her?

Sam strutted through the large oak door, and was startled as soon as he stepped outside. There, before him, were dozens of Aiden's men, sprinting across the courtyard and leaping up into flight. It looked as if the entire coven were mobilizing for war. The excitement in the air was palpable.

Sam reached out and grabbed one of the vampires. "What's going on? Where are you going?"

"Haven't you heard?" he asked, stopping for just a moment, his eyes wide open in agitation.

"London is besieged. Fires have started everywhere. The plague has spread to all four corners. And someone has unleashed a rival vampire coven from the crypts - they are now attacking the humans.

The entire human population is under a coordinated attack. We sense that it's the work of a rival vampire coven. We have to save the humans before the city disappears." With that, he shook off Sam's grip and leapt into the air, flying with the others. The sky darkened with all the bodies, looking like a swarm of bats launching into the sky.

Sam looked up and saw Aiden, walking behind them all, watching the sky. He turned and looked at Sam.

"There is a great calamity among the human race. I must join this battle," he announced. "You are alone here now. I trust you to watch over our castle."

Sam didn't know what to make of it.

"I want to go, too," he said. "I want to fight with you. I don't want to just sit here."

"We don't only always do what we want. We do what is needed of us," Aiden responded. Then he turned to go.

"Wait!" Sam yelled out.

Aiden turned.

"Where is Polly? Did she go with you?"

Sam sensed deep down that something was off.

Aiden slowly shook his head, staring intently at Sam.

"Polly left hours ago. Before us. With Sergei."

Sam's heart dropped. With Sergei?

"She is in grave danger," Aiden added.

And with that, he turned and suddenly disappeared. Sam looked everywhere for him, but he was gone. Vanished.

Aiden's final words lingered, like a dagger thrust into Sam's heart.

In grave danger? With Sergei?

Sam closed his eyes and tuned in, and suddenly, he sensed it. He could feel that it was true. He could feel, on some level, Polly calling out to him. In danger. Trapped.

Sam opened his eyes suddenly, feeling Polly's desperation. He couldn't bear it one second longer.

Without thinking, he took three running steps and leapt high into the air, flying faster than he ever thought he could, letting his body guide him in the direction in which he felt Polly was. He didn't have a choice. She was trapped, and he must save her.

In his haste, he didn't even give a second's thought to the fact that Lily was now the only one left behind, a mere human, to guard to their castle, and two people on their deathbed.