Sherlock bound into Lestrade's flat like a bloodhound, knocking over a lamp in hot pursuit.

"Alright, alright, sit down, won't you? I'll grab them." The older man disappeared into his bedroom, returning with a manila folder bursting with cold cases. Sherlock had obeyed by falling onto the couch.

"No, not there! You're sopping wet!"

The detective jumped up, looking apologetic. Greg sighed, cursing himself. "Sorry. Not your fault; I told you to sit. Just…" He left again, returning with a pair of basketball shorts, fresh socks, and a green t-shirt. Sherlock shook his head. "Don't be difficult, Sherlock. You're here to have fun, yeah? Go get comfortable and we can dig right in."

Sherlock did as he was told, grabbing the cases off the counter as he returned to the couch. He opened the first file, losing himself in the details immediately. Greg watched from the kitchen, preparing tea on a platter.

"Does your dad let you have biscuits at night?"

Sherlock shook his head, not looking up from his work.

"We won't tell him then, will we?"

The detective grinned, grabbing a few as Lestrade settled next to him. By the third page, the biscuits were gone and Sherlock was reading upside down, head comfortably resting on Greg's lap.

"Sherlock?" Greg gently took the folder and dropped it on the side table. "You never did explain today's case to me."

The detective began signing.

Greg laughed. "I didn't know you could do that. I don't speak it, though. Neither does Joh—er, you're father. I've never known you to be silent. Come on. What cat's got your tongue?"

Sherlock seemed to consider a moment; his brow furrowed and, after a moment, his eyes looked up and back to see the inspector's face. His voice was small. "Dad's mad at me."

Lestrade jumped, surprised to hear anything so soon. "Mad? Why would he be mad at you?"

"Well, he's going to be. Once he finds out."

….

John opened his door at ten the next morning and immediately asked what was wrong.

Greg, realizing Sherlock was hiding behind him, dragged the detective forward. "Go on."

Sherlock eyed the floor. "Dad, I…"

"You're talking!"

"And he's got something to say, John. Don't you, Sherlock? Go on, now." Lestrade's tone was serious, but a slight smile played on his lips.

"I…have Redbeard," Sherlock said, barely audible.

John stared. "You what?"

"I have Redbeard."

"Sherlock, Redbeard's—"

"I know. But I didn't want him to be, so…I got another Redbeard."

John looked at Greg, who was trying not to laugh.

"What do you mean you've got another one, Sherlock?" John asked. He himself was trying to suppress his growing anger.

"I found him at the park and brought him home a few weeks ago." His volume and rate suddenly increased. "I know you don't want another pet, Dad, but he's good. Please let me keep him. I've been taking care of him; you haven't even noticed! Please?"

John bit his lip. "Where is he?"

Eyes returned to the floor. Greg answered for him. "Check under the sink."

John cursed; Lestrade used all of his effort to remain stoic in front of Sherlock.

"A duckling?!"

Sherlock still maintained contact with the floor, sniffling and trying to hide a tear. John huffed, handed the brown and yellow spotted creature to Greg (giving the inspector a glare as he did so), and led Sherlock to the couch. He kneeled in front of him, demanding full attention. "Why is there a duck in the flat?"

"He's Redbeard the Second."

"That didn't answer my question, Sherlock."

"Can't he stay?"

John inhaled. "This is why you haven't been talking?"

Sherlock shrugged. "I thought I'd give the secret away if I said anything."

John threw his hands in the air, glancing again at Greg. "Could you not laugh in front of him? This is serious."

Lestrade nodded. "I know. I know. Sorry. We talked about it for quite some time last night. Sherlock, you shouldn't have hidden this from your Dad."

"How are you feeding him? Where did you get him?"

Sherlock didn't answer; Lestrade nudged him. "I told you, I found him at the park. He was alone; I didn't steal him from anyone. I just drop bits of food during meals to save for later. He doesn't need much, Dad. Neither of us do."

"When did you go to the park?"

"I go there all the time, mostly when I can't sleep. It helps me think."

"You go to the park at night? Alone?"

"Well yeah, but—"

"Do you know how dangerous that is?! Sherlock, what if something happened to you? I would have no clue where you were; how would I help you? You know to always tell me where you are; you know that. There's no excuse for what you've done."

A feeble nod. "I'm sorry."

John pinched his nose. Here he was, yelling at a thirty-eight-year-old-Sherlock-gone-eight for smuggling a duckling into the flat, not eating his meals, resorting to mutism, and exploring London solo in the middle of the night.

"Sherlock. I'm not happy with you. You shouldn't have lied, or adopted a pet without telling me, or stopped communicating with me. Yes, I'm cross, but I would have been far less upset had you been clear with me from the start. I'm most upset about you keeping things from me; I'm your protector, right? Your soldier. I can't be that unless you help me."

Sherlock nodded, accepting the hug by burying his face into the crook of John's neck. The doctor mouthed a silent thanks to Lestrade, who tipped an imaginary hat before slipping out.

"Dad?" Sherlock said, still muffled.

"Hmm?"

"I know I'll be punished. But don't tell that man, okay?"

John removed him from his shoulder. "What man, Sherlock?"

"Mycroft. Don't tell him that I tried to replace Redbeard."

John searched the detective's eyes. All Sherlock knew about Mycroft was from the one encounter a couple weeks ago. "Why would I tell him, Sherlock?"

Sherlock tried to return to John's shoulder, but he kept him up. "'Don't get involved.' That's what he said. He'll be disappointed in me, Dad, if you tell him."

"Disappointed? Why…Sherlock, when did he tell you that? And why do you care what he thinks?"

He thought for a moment. "I don't know. A long time ago, I think. It's one of those memories that are still fuzzy. Promise you won't tell him?"

John hummed, letting Sherlock lean back against him. No, he didn't promise.