Harry Potter/Sherlock fanfiction
I'm looking for a Harry Potter/Sherlock crossover where I am pretty sure Harry is either Sherlock's son or nephew. The only scene I remember is that I believe both Mycroft and Sherlock are in Dumbledore's office and Harry walks in. Sherlock immediately starts deducing him and make Harry mad. Harry deduces him back in retaliation. Not sure if Harry knew about what was going on beforehand or not.