Parallels between the BBC programme "Sherlock" and Sir Arthur Conan Doyle's novel. For nerdy purposes. Asterisks indicate direct parallels.

• Dr. John Watson has returned from Afghanistan*, has sustained an injury to his leg*.
• Watson chronicles his adventures with Sherlock.
  • Watson's journal.
  • Watson's blog.
• The two pills*.
  • One being poison, the other harmless.
  • Forcefully given.
• Detective Inspectors Gregson and Lestrade are morphed into Greg Lestrade.
• A friend of Watson helps him to gain Sherlock Holmes as flatmate*.
• Watson is unable to afford living by himself*.
• Mentioned for only about a sentence and half, Sherlock does actually conduct beatings on the dead bodies for scientific inquiry*.
• Sherlock is able to gather that Watson came back from Afghanistan the same way he does in Scarlet.
• Sherlock asking whether Watson minds the violin*.
• Sherlock is able to gain information about Watson's sibling from an item that is handed down to Watson.
  • Sibling is a drinker*.
  • A watch, handed from father H.W. to son H.W.
  • A cell phone, given as a gift to Harriet "Harry" Watson by her partner.
  • Watch key-windup parallel to the electrical port on the cell phone.
• Same address--221B Baker Street*.
• The “three-patch problem” of nicotine references a quote from The Adventures of Sherlock Holmes, “To smoke,” he answered. “It is quite a three pipe problem. and I beg that you won’t speak to me for fifty minutes.” Preludes the cocaine injections.
• The theme of the common and the uncommon, the ordinary and the extraordinary is prevalent throughout the text of Scarlet. For those who have watched Season Two, this remains the main theme, as Jim Moriarty never fails to remind you.
• The killer has a time-bomb of an illness, and therefore has very little to lose.
  • Aortic aneurysm.
  • Brain aneurysm.
• A woman's ring.
  • Lucy's ring from the marriage to Drebber.
  • Jennifer's marriage ring of 10+ years.
• Multiple partners.
  • The Mormon customs.
  • Jennifer, the serial adulterer.
• The killers kill for the benefit of someone they love.
  • To avenge the deaths of Lucy and Ferrier.
  • To impart money to his children.
• "Rache".
  • Gobbledygook. Interpreted by Sherlock is as the German word for "revenge" and by the inspectors as "Rachel". In the end though, "rache" is just to lead off the police--because the killer saw a similar element in a crime in Germany that puzzled investigators.
  • The password to the victim's email.
• The killer is a "cabbie".
  • Hansom cab.
  • Automobile.
• The title itself.
  • "Scarlet" refers to a statement made by Sherlock: "There's a scarlet thread of murder running through the colourless skein of life, and our duty is to unravel it, and isolate it, and expose every inch of it."
  • Watson just thinks it's a great pun for the pink-coordinated victim.
• The killer makes a mistake.
  • Hope leaves the ring he used to remind Drebber of Lucy in the abandoned building and must go back to get it.
  • The cabbie gets stuck with the pink case.