8. Blood is Thicker

Complete story — includes the ending

A woman named Haley Tyler dies after being stabbed, falling off a balcony and landing on a truck. Haley was the illegitimate daughter of technology mogul Ian Gale, who is dying and needs a transplant. She had the same rare blood type as Gale, and had been donating blood to him. Evidence points to Gale's wife Natalie due to a will amendment giving 20% to Haley, as well as the precise location of the stabbing, suggesting medical knowledge; Mrs. Gale was a doctor. However, Mrs. Gale suggested the will change herself. Haley turns out to have been ill the week before she died. Ian later dies. Mrs. Gale turns out to have murdered both Haley and Ian: she gave Haley medicine that made her body overproduce antibodies; transfusions of her blood killed Ian, and Mrs. Gale murdered Haley to remove a loose end. Mycroft, who plans to return to London soon, proposes that Sherlock come along, saying that Morland desires it. Sherlock refuses the offer, giving a letter to Mycroft to pass on to Morland. Later, Mycroft shreds the letter; he lied to Sherlock and wants him out of New York for other reasons.