atson tries to process that she has a sister. She and Sherlock get a case, a girl was shot and then taken somewhere else. Watson thinks she knows her, she later recalls that the girl's picture is in some gallery where selfies are exhibited. They learn that some of the people whose pictures are in the gallery don't like it. And they talk to one of them who took some pictures of the pictures being exhibited. When Sherlock sees the victim's picture he says that the one is the gallery is not the original. They learn someone broke in and took some pictures but Sherlock thinks it was a cover to hide that they took the girl's picture and replaced it. Sherlock thinks that in the corner of the original picture is a faint shot of a man and it turns out that it's a man who was convicted of murder two years ago. But the picture shows that he was there at the time of the murder. So they talk to the prosecutor who maintains that he is guilty because of DNA evidence. Sherlock then investigates and thinks the tech who did the test might not have been impartial.

Résumé de IMDb.com