"That still doesn't change what happened," Sherlock replied. "The man was killed with acetylhydrolase, an ingredient in common household flea killer. The poisoning wouldn't have been immediate, it likely would have taken some time to reach full effect, and by that point an alibi could have been established."

"You need a better argument than that for them to actually arrest," Elena said quietly.

"You can't prove anything and I didn't do anything." Kelly crossed her arms over her chest.

"It's enough to have you held for further questioning," Sherlock said. And he definitely intended to have Lestrade keep her until she was proven innocent of the whole thing. And he knew she wasn't, he just had to prove it.

"Come on, Sherlock," Elena murmured, herding him out of the room. "She'll stay there, you've got 48 hours to find something more solid."

Sherlock just growled wordlessly as he paced the hall. There had to be something, something he had missed at first. Wife, affair, accident, sister, dog, murder. What else was there?

"Murder weapon," Elena murmured. "Make sure she has the murder weapon, start testing dishes and food, if she cooked there are likely traces in the leftover food. She's not perfect, she has to have left some trail."

Sherlock blinked and looked at her.

"I'm sure I haven't said anything aloud," he said.

"You haven't, but you've got your frustrated look, and you're pacing. You haven't quite got everything or else you'd be running straight back in there or off to Lestrade." Elena shrugged. "Come on, her apartment, or back to his, let's go."

"We will need to check both," Sherlock said. "Nothing points to where she made the food." He grumbled. "I hate not knowing things."

"It's possible she cooked at both places, but I'd go to his place and check the food there first. I doubt she kept poisoned food around her place." Elena shrugged.

"I doubt she kept it around at all," Sherlock said. "And why leave the murder weapon in the victim's home? Far more likely she cooked it at her own home and then brought it to him. But both places should be checked."

"Let's start with his place, we know we can get in there," Elena said, heading for the door and expecting him to follow.

Sherlock frowned a bit even as he followed. He wasn't used to anyone taking charge around him; he was far more used to leading the idiots around by their noses. Somehow it was almost... refreshing.

Elena even called the taxi for them, settling in next to Sherlock for the ride.

"Should I look at anything else besides the food?"

"Food, drink, the trash, perhaps," Sherlock said. "Anything that could have been in contact with the flea killer."

"Right. He had an appointment book too, I think," Elena said. "Look through that, see how often he saw Kelly."

Sherlock nodded. Elena was picking up on his methods surprisingly quickly. He kind of admired it. Privately. Where nobody could see.

Elena got out first and went to go shove the window open again, going straight to the kitchen and starting to investigate everything.

It took her several minutes to find anything, and then she paused. "I think I got it," she called.

Sherlock went into the kitchen, even though he would never admit to being curious.

"What did you find?" he asked.

Elena had out the cleaner Kelly had likely used on the counter, along with some food that she'd missed when cleaning out her fridge.

"The fridge is mostly empty, but there were a few things left in there. One of them even still has a note on it." She pointed to the container, which had apparently been meant to be eaten for lunch.

Hi honey! Here's that special lunch you asked me for! Call me about Friday. Love, Kelly.

Raising an eyebrow, Sherlock pulled on his gloves and then reached in to pull out the container. He wrinkled his nose in distaste when he opened the container; it was starting to go a little fuzzy and moldy, but there was still a distinctly acrid smell about the food, one that he couldn't attribute to the growth of the mold.

"I do believe you found what we're looking for," he said, closing the container again.

Elena grinned, feeling rather smug about that. "Great. Do we need anything else here?"

"We should still investigate her flat," Sherlock said. "Perhaps she's made things easy for us and left the chemical there."

"That would be nice," Elena agreed. "I'll let Lestrade know we found some things here so he should come investigate." It took her only moments to send off the text, waiting for a reply before she nodded and looked at Sherlock again.

Sherlock nodded once, put the container back into the refrigerator, and then gestured to the door.