John briefly glanced at Sherlock before opening the Tardis door. "Mary," he said, "We're back."
There was no reply.
"Mary?" John called as he stepped into his apartment.
Sherlock followed him and looked around. The coffee table was skewed from the angle it normally sat at, the recliner's lever to raise the foot stood half turned, and the magazine and book on the end table between the chairs were perfectly stack and lay perfectly parallel with the table's edge. Everything in that room was slightly off, clear signs of tidying up quickly after a scuffle.
"She's not here, John," Sherlock said.
"Of course, she's here," John argued. He headed towards the bedroom.
"John, I wouldn't go in there," Sherlock said.
"Oh my God. Sherlock!" John shouted.
Sherlock followed after him.
On John and Mary's bed sat a white marble headstone engraved with the words "I Owe You."
Sherlock pulled John's arm to lead him away from the room.
"No," John said, "What does that mean?"
Sherlock turned John away from the tombstone. "It means Moriarty has Mary," he said. Sherlock pulled John towards the Tardis.
"He can't have Mary," John said.
Sherlock said, "He does, John. He does have her. We have to go."
"He can't have Mary. He can't have her. He can't have my family. He just can't," John said.
Sherlock had the feeling that this would be an appropriate time to hug his friend, but he wasn't quite sure enough to do it.
"We're going to find her," Sherlock said to reassure John, "Don't worry. Let's go back to the Tardis, and we'll figure it out."
John didn't react but walked to the Tardis with a certain level of determination that reminded Sherlock of the intensity John's motions had after he discovered the truth, or what part of it he cared to know, about his wife. Sherlock began to worry about John. They had to find Mary. Losing her and their baby would destroy John. It didn't matter what feelings John and Sherlock had confessed to; Mary came first, and she always would.
As they stepped into the Tardis, Cas glanced at John and asked, "What's going on?"
"Moriarty has Mary," Sherlock explained, still watching John. The fact that this was Moriarty's doing probably did nothing to help John's troubled mind.
Dean's phone rang in his pocket.
"Sam," Dean answered, "You need to get back here. John's wife is missing...Apparently, Moriarty happened." He paused for a moment. "Are you shitting me right now?" he asked, agitated. Sherlock thought he saw Dean's eyes turn black for a moment, but it could have easily been the lighting.
Cas gave Dean a worried look, and Gabriel sighed, "I did not just hear that."
"Hear what?" River asked.
"There's another weeping angel on the loose," Dean said, "And Sam and the Doctor need a lift."
The Tardis materialized at Sam and the Doctor's location two seconds later.
"Where's the new angel?" River asked.
"We don't know," Sam said.
The Doctor said, "Sam blinked."
"Because you gave me no warning!" Sam protested.
"So, we have to start searching again," Sherlock said, "Or think of a better trap since I doubt Moriarty will allow us to take another weeping angel away from him."
"No, we need to get Mary back," John snapped.
"Oh, that's what happened," the Doctor said, "I was wondering. But we'll have to take care of the weeping angel first, sorry."
John started, "No, I don't think you underst-"
"If Moriarty has your wife, he's using her as leverage, so she'll stay alive. I can't say the same for anyone who runs into a weeping angel in the meantime," the Doctor said quickly.
"Actually, Doctor," Sherlock said, looking over at John, "Moriarty is a psychopath. Assuming he'd let her live to use her as leverage would be assuming that he's using a logical thought process. We have to get to Mary first."
The Doctor sighed, "She might possibly die whereas countless people in London will die if we don't stop that angel. Do you even know where Mary is?"
Sherlock said, "No, but my grave would be the first step to finding her."
"Your grave?" John asked, "Why?"
"Moriarty said he had marble angels. These angels are definitely not made of marble, and he wouldn't make a mistake like that. Also, the headstone in your bed was made of marble. Probably not a coincidence. The only marble relating to me is my gravestone," Sherlock said, "Then, the headstone said 'I Owe You.' When Moriarty was with me on the rooftop and several times before that, he said he owed me a fall. He even carved it into an apple once. My grave is the only thing that makes sense."
River looked at the Doctor for an idea of what she should do.
The Doctor sighed, "Fine. We'll go to your grave, but if it doesn't spell out exactly where Mary is, we have to go after that angel."
As the Tardis materialized in the cemetery, Sherlock said to John, "We'll find her."
John said quickly, "You're damn right we will."
The black marble headstone stood shining in the sunlight. Sherlock stepped closer to investigate. Nothing seemed particularly out of place. But he had to find Mary. Not only for John. He had made a vow to protect them. He wouldn't break that now. He was still struggling with the fact that Moriarty was alive let alone kidnapping the people he cared about.
Cas watched Sherlock circle the headstone.
"Can I help you?" Sherlock asked.
Cas tilted his head to the side and said, "You're very detail oriented for a human, but you've completely avoided looking at your own name. It's intriguing."
"Don't psychoanalyze me," Sherlock warned.
But Cas was right. He had avoided his own name. Quickly, he circled the gravestone and looked at the engraved lettering. And there is was. Inside the 'O' in 'Sherlock' had been engraved three marks, turning the 'O' into a smiley face like the one he'd spray painted on his wall.
"She's at Baker Street," Sherlock called.
John rushed over and asked, "How do you know?"
Sherlock pointed at his name when his phone rang. Quickly, he answered it, "Hello?"
"Sherlock?" Molly said, "I think I need your help."
"Either you need my help or you don't, Molly," Sherlock said.
Molly said quietly, "I saw an angel statue outside the window, or I thought I did. Now, it's gone, but I heard some commotion upstairs."
"Where are you?" Sherlock asked.
"The morgue like always," she said.
"We'll be right there," he said, hanging up the phone.
"But you just said you figured out where Mary is," John said sternly.
Sherlock went back into the Tardis. "The angel is at St. Barts, but Mary is at Baker Street," he said, "We have to go for Mary."
The Doctor said quickly, "Alright, we're not discussing this again. We'll split up. You two go to Baker Street. The rest of us will go to the hospital."
The cemetery wasn't far from Baker Street. Shouldn't take more than a few minutes to run. Sherlock stepped back out of the Tardis and grabbed John's hand.
"Are you going to be okay?" Sherlock asked.
John nodded and said, "Once we get Mary, yes."
"Okay," Sherlock said, "Let's go get your wife."
Together, they ran off towards Baker Street while the Tardis dematerialized behind them.