A strange clue in an empty room, a blood-soaked car, a priceless Old Master, a deranged bomber. With the clock ticking, the curtain rises on a battle of wits between Sherlock, John and the shadowy stranger who seems to know all the answers...

• Steven Moffat
• Arthur Conan Doyle
• Mark Gatiss

• Toby Jones
• Amanda Abbington
• Amanda Root