Prompt from Ennui Enigma: Lestrade solves the case.
Holmes paced back and forth, muttering furiously. Watson had been missing all day, and Holmes could find no trace of him. Normally, this would not be a matter of concern, but Holmes was currently in the middle of a rather dangerous case, and was afraid the men he was trying to track down may have done something to harm Watson.
He paced back towards Watson's desk, keen grey eyes scanning the contents. Everything was as usual, with the exception of a single petal of what looked to be a marigold.
An idea struck him, and he turned to his shelf, rifling through for a small book he had picked up on a previous case. He looked through for the correct entry, and took a sharp breath. Marigolds, in the old flower language, could mean creativity and passion, or they could mean cruelty, jealousy, and grief. If someone had taken Watson and left these as a sign, that could only be a bad thing.
His only relief was that he could see no impressions on the carpet or unusual scents to suggest someone had been in the room, but that alone was not enough to be sure it hadn't happened. An absence of something was not enough to rule out its existence.
He heard clomping footsteps on the stair, and soon Lestrade came into the room. "Any progress, Holmes?"
"I fear they may have escalated beyond my suspicions." Lestrade didn't seem to understand, so he spoke more plainly. "Watson is missing."
Lestrade's eyes glanced over Watson's desk, and settled on the petal Holmes had been examining earlier. "Have you checked Mary's grave?" He looked back at Holmes. "It's the anniversary, after all."
"No," Holmes said quietly, his pacing stilling. He had known Mary died, but he had not been there to know the date it happened, and Watson had not told him. "I will send someone to check. Thank you, Lestrade."
"Not often I get to solve a case before the great detective." Lestrade smiled sadly. "Don't bother sending someone. I'll go myself."