A/N Sherlock and Black Widow.
Sherlock: *does chemistry experiment*
Black Widow: *breaks into flat*
Sherlock: *raises eyebrow*
Black Widow: *watches experiment*
Sherlock: *continues doing experiment*
Black Widow: *goes over* Can I help?
Sherlock: *raises eyebrow* Chemistry set is over there, beakers over there, working space here. Use rubber gloves if you want to, if you don't, don't.
Black Widow: *gets chemistry set, grabs beakers, stands next to Sherlock, and starts experimenting*
TWO HOURS LATER
Black Widow: *watch beeps* *looks at watch* I have to go.
Sherlock: *looks at her* Pity I was enjoying your company.
Black Widow: Yeah, well all good things must come to an end. *goes to window*
Sherlock: *looks up* Come again some time soon. Oh and, are you part of the Avenger what-sit team?
Black Widow: *smirks* Yes, yes I am (Whovian quote there) and it's The Avengers.
Sherlock: *nods* You're the only one who hasn't damaged anything, and was actually quiet.
Black Widow: Thanks. *turns to go*
Sherlock: Oh and tell Mr. Genius-Billionare Playboy-Philanthropic to fix my wall, and Loki of Asguard to stop being so damn annoying.
Black Widow: *smirks* Consider it done.