Benedict Cumberbatch’s super sleuth faces off against the deadly Charles Augustus Magnussen in tonight’s heart-stopping climax to Sherlock series 3.

UPDATE: Read our recap of tonight’s episode!

After two years of waiting, the third run of Sherlock is over less than two weeks after it began. We’ve been promised a return to a case-driven narrative, a chilling villain, and ANOTHER tense cliffhanger. If you’ve felt slightly let down by the lighter tones of the previous two episodes, it looks like “His Last Vow” will provide you with all the Sherlock thrills you could ask for. Check out the episode’s synopsis below.

“Sherlock Holmes encounters Charles Augustus Magnussen, the one man he truly hates, through a case of stolen letters. How will he tackle an enemy who specialises in blackmail and knows the personal weakness of every eminent person in the Western world?”

Previously on ‘Sherlock’

After saving the life of John’s military superior James Sholto and solving an unresolved case to boot, Sherlock finally delivered a heart warming best man’s speech and got the happy couple off to a great start with a beautiful waltz. After revealing that Mary was expecting his former flatmate’s child, the great detective sneaked out into the shadows, alone. But lest we forget, the melancholic Charles Augustus Magnussen (Lars Mikkelsen) has been lurking in shadows of his own, watching the Baker Street boys’ every move…

Tonight, the show’s new villain comes out of his creepy theatre and squares up to Sherlock and co. with deadly consequences. Check out the trailer for “His Last Vow,” based on the Arthur Conan Doyle story “The Adventure of Charles Augustus Milverton” below!

The episode airs in the U.K. tonight at 8.30 pm GMT on BBC One. American viewers can catch the episode when the series returns next week.

What are you most looking forward to in ‘His Last Vow’?