Sisterly Love (BBC Sherlock) (Johnlock)

Elizabeth Holmes, younger sister to Sherlock Holmes, is what you could call a criminal mastermind. To avoid many catastrophic conflicts, the two usually try to give each other a wide berth. But a recent series of events has caused Lizzy to come to her brother for help. The relationship between the two is strained already, but to make matters worse, Lizzy has her sights set on John, and doesn't mind hurting her own brother to get him.