Around noon
Just as Sherlock was finishing up a chemical experiment, his arm bumped some of the chemicals and spilled them over the table. As he looked to see what had been destroyed this time, he froze as he saw he had ruined Watson's favorite jacket. Worse, he heard Watson coming down the stairs.
In a panic, he threw the coat behind one of the desks and pretended to wrap a package.
Watson walked in and Holmes waited for the bomb to go off.
"Sherlock," Watson said as his friend was wrapping a package, "Have you seen my coat?"
"Which one?" Sherlock asked as he put the package away.
"My nice coat, the grey one I keep in the closet?"
"Oh, Miss Hudson took it to the cleaners."
"Thanks." Watson said as he walked out of the room.
Sherlock waited for a few moments and then walked to the other side of the room. As quietly as he could, Holmes pulled the chemical burned jacket out from behind his desk and tried to burn it as fast as possible.