Sherlock, John and Sam stayed at the stable until the local police showed up to take Archie in for further questioning. As it turned out, Eve Hunter had visited the stables once she found out her husband owned the horses. She was not about to let him get away with hidden assets when it came to the divorce. She had spoken with Archie, who had given her the financial information, but that was the one and only time he had ever met her. When asked why he didn't go to the police with this information during the initial investigation, Archie admitted he was afraid that the suspicion would turn towards him. With his precarious standing with the law, he felt that he would have been rushed to judgement. Sam watched carefully while he was questioned, and felt that we was being truthful now. The police, however, did detain Archie until further information could be collected. There was only one thing left to do…
Sam drove John and Sherlock back to London to the lab at St. Bart's Hospital. Sherlock had been able to secure blood samples taken from the Hunter home in the initial investigation, thanks to Molly Hooper.
Molly was waiting for them with samples and the chemicals Sherlock had requested for testing. When Sherlock entered the lab and saw Molly standing there, a fleeting expression crossed his face that was not lost on Sam Sloan. Had that been fondness? Affection? Maybe John Watson wasn't the only one who affected Sherlock this way.
Molly smiled at Sherlock and could no more control the look of hopeless adoration on her face than she could control the weather. Sam was touched by this. The Genius was human after all.
"What are you looking for?" asked Molly shyly.
"Acepromazine," said Sherlock, not looking up from his microscope. "If I am right, this blood sample should contain it."
"Wouldn't they have tested the blood when they first collected it?" asked Sam.
"They tested it for DNA and perhaps a few well-known compounds, but this requires a very specific test. They wouldn't have been looking for it," he explained, as if to a simple minded person. Molly Hooper didn't even try to hide her smirk. This was her territory. Molly was clearly intimidated by Sam's striking appearance, but Sherlock seemed impervious to it. At least, it seemed that way to Molly.
"Aha!" exclaimed Sherlock suddenly, causing them to jump a bit. "We've got it!" he said with obvious glee. "The small amount of blood in the house is consistent with someone being stabbed with a needle, not a knife. The amount of the drug necessary to knock out a horse would have killed a human."
"But we still don't know who did it," John reminded him. "It could have been Archie. He is a vet, and he had direct access to that drug."
"I didn't get that sense from him," said Sam, confident in her ability to read people.
"Archie had no motive," said Sherlock. "Karl was hiding his equine assets, and once she found him out, perhaps he became incensed."
"We don't have a body," Molly reminded them sensibly.
"Molly's right," said Sherlock turning to Molly with an approving look. She was visibly pleased at this small attention.
"We need to find that body," he said, filled with a new vigor. The others were clearly tired from the long day of running around, but Sherlock seemed as fresh as ever. He was indefatigable when on a case.
"Where would a man like Karl Hunter hide a body?" said Sherlock, pacing around the lab.
"And with just a few drops of blood found, he didn't chop her up," said Molly matter-of-factly with her quirky smile. Sherlock did admire her practicality and lack of squeamishness.
"He would have had to have gotten the body out of the house fast with the kids around," said John.
"A man like that who hides money from his wife and then kills her," said Molly hotly. "He treated her like horse shit in life, so maybe he would treat her that way in death."
They all stopped talking to take this in.
"You…you don't think he…" began John.
"Composted her?" finished Sherlock. "I think we need to pay Mr. Hunter a little visit," he added menacingly. And with that, he strode purposefully out of the lab.
John hesitated before following. "Molly, can you tell Lestrade about the horse tranquilizer Sherlock found? I'd like a chance to see if we can find the body before the police swarm the place, but I also want to make sure Hunter doesn't disappear on us."
Molly nodded. "I'm on it."
Sam wasn't sure what to do at this point. "Do you mind if I come with you?" she asked. "I might be able to help."
"Sure, Sam. Come on, then. Sherlock doesn't like to be kept waiting," said John as they ran after him. "I can't believe I just said that," he muttered under his breath as they raced out onto the London streets.