Benedict Cumberbatch Faces His Demons In New Trailer For 'Sherlock' Season 4

“The roads we walk have demons beneath, and yours have been waiting for a very long time,” intones the intense voiceover in the new trailer for “Sherlock” season 4. As usual, the show’s writers are keeping as much as they can under lock and key, but it looks like Benedict Cumberbatch and Martin Freeman will be going to some very serious places in the latest installment of the hit series.

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“It’s no spoiler: We explicitly said it is the darkest season yet and still obviously full of laughs and fun, but is generally tonally dark,” co-creator Mark Gatiss told EW. Apparently, the new season will be inspired by the 1913 Holmes story “The Dying Detective,” with Toby Jones taking the villain role and looking like he’s really relishing it. If that’s the case, that means the plot may see Sherlock himself in the middle of a murder plot.

For fans, it looks like another season to get excited about, but they’ll have to wait — “Sherlock” won’t return until 2017.