Lara Pulver is Irene Adler in the BBC’s Sherlock

It’s elementary, dear Watson: Irene Adler has been cast in the second season of the BBC’s “Sherlock”, and she’ll be played by “True Blood” and “Spooks” star Lara Pulver. Den of Geek reports that the actress will star opposite Benedict Cumberbatch (still the greatest name for an actor EVER) in the first episode of “Sherlock'” season 2, titled, “A Scandal In Belgravia”.

The 90-minute episode will be written by show creator Steven Moffat, and will be the first of three 90-minute episodes that make up the second season (or second series as they call it Across the Pond) of “Sherlock”, the BBC’s hit contemporary take on the legendary Arthur Conan Doyle detective. Martin Freeman, currently doing the Hobbit thing on Peter Jackson’s “The Hobbit”, plays smarty pants Sherlock’s sidekick, Dr. Watson, an Afghanistan war vet who is quite possibly the only man alive who can tolerate Sherlock.

As you might recall, Rachael McAdams recently played Adler in Guy Ritchie’s big-screen “Sherlock Holmes” movie opposite Robert Downey Jr. The Adler character has always been an American (hailing from New Jersey, natch) in the Doyle stories, and not just a love interest for Sherlock, but the love interest.

Originally scheduled to bow in late 2011, “Sherlock” will now be delayed until 2012.

Meanwhile, Lara Pulver is no Rachel McAdams, but she’ll do.