"You'd better put this on," the Doctor handed Donna a ring. "Bio damper."

Donna made a face. "What?!"

"Simply put, it'll neutralize those parts of your inferior human biology that would activate the temporal sensors on their plasma residue detectors, and then..." the Doctor noticed her dazed look and realized that maybe she didn't speak Timelord. "Oh, well, it, um, it'll keep those evil Santa things from finding you."

"Thanks." She nodded curtly.

He slipped the ring onto her finger, then did a double-take. That wasn't the bio damper ring! That was- oh, nevermind... He must've grabbed the wrong ring. Oops. Too late now. If he switched the rings now, Donna would ask questions he really didn't want to answer. He silently prayed that she wouldn't question anything. Of course, the next thing out of her mouth was the very question he had been dreading.

"Why've you got a ring?"

He groaned. "That is none of your business, young lady."

"Oi, spaceman! Watch it!" She acted offended, then pressed on. "Is there... someone special?" She looked at him searchingly.

He avoided her gaze. "Yeah, there was. But I- she- I don't want to talk about it. Now, can we please get back to the issue at hand?"

"Fine. One more question, though."

Ugh, here she went again. Were all humans this inquisitive? Rose was inquisitive, but never downright nosy!

"Fine. Let's get it over with. What?" He asked, irritated.

"Did you love her?"

He chuckled softly at her naïveté and his face softened. "Yeah. Of course I did. I was going to propose on Diamata, under the pink sky, with the moon setting over the chocolate lake, on top of the strawberry grass, and then- no. Not anymore. I lost her. She's gone, because of me." He buried his face in his hands.

"What- what happened to her? Doctor?"

He stared into space, images flashing in his mind, slowly wearing his defenses down.

"I lost her. She's gone. That's it."

His eyes took on a glazed over and haunted look. He ran his hands through his messy, disheveled hair. He murmured to himself, almost incoherently, "Daleks, and Cybermen, the Void, Pete's World, oh, Rose! I'm burning up a sun... I lo-" He shook his head as if trying to block the stream of thoughts and images invading his brain. He was shaking violently.

"I never told her. I had so many chances, and I never told her." He rubbed his face with his hands.

"You never told her what?" Donna touched his shoulder tenderly.

He couldn't help remembering the most prominent opportunity that he had missed. He could still see the tears in Rose's eyes.

"But... Sarah Jane... you were that close to her once, and now... you never even mention her. Why not?" Rose was on the verge of tears.

"I don't age. I regenerate. But humans decay. You wither and you die. Imagine watching that happen to someone who you l-"

"Someone who you... love." He mouthed. "I... love her. Rose Tyler, I love you to Raxicoricofallapatorious and back! Why can't you be here? It's all my fault. I have to tell you!" He was lost inside his head.

Donna's thumb grazed his shoulder calmingly. "I'm sorry. I didn't know. I shouldn't have pried. I'm sorry, Doctor."

He snapped back to reality and, as per usual, tried to cover up his deep sadness with his bright and chipper attitude. "Huh? Oh, it's alright. Now, where were we?"

"Er- Evil Santas." Donna was more than a bit confused and put-off by this point.

"Right then. Allons-y!"

"You'd better put this on," the Doctor handed Donna a ring. "Bio damper."