'Sherlock' season 4 spoilers, updates: Sherlock to die? Benedict Cumberbatch out for season 5?

The time could be up for one of the main characters of BBC's hit series, "Sherlock." At least, that's what the latest spoilers for the show's upcoming fourth season seem to hint.

At the start of "Sherlock" season 4's filming in April, series co-creator Steven Moffat already gave a heads up of the upcoming season. He told Collider that "terror and tragedy" loom for Sherlock (Benedict Cumberbatch) and his ever-reliable pal John Watson (Martin Freeman).

With production having wrapped up on Aug. 5, co-creator Mark Gatiss' recent tweet seem to confirm Moffat's words. Check out the post below.

The image of what looks like Sherlock's multi-tool knife pinning an envelope bearing his name and home address seem to be a portent of ominous things for the beloved detective. Could Sherlock's impending fate have anything to do with season 4's villain? There have been reports that "Sherlock" season 4 will feature a villain more menacing than James Moriarty (Andrew Scott), which Toby Jones will be playing.

Den of Geek has named Jones' character as the villainous Culverton Smith, who was the main antagonist in Arthur Conan Doyle's short story "The Dying Detective." In said story, Sherlock fell sick because Culverton pulled an underhanded scheme on him. The story even showed Culverton taking sheer delight as he watched Sherlock die.

Meanwhile, reports are rife that "Sherlock" season 4 would be the last one for Cumberbatch. In a separate interview with Collider, he hinted that the upcoming season could be his personal swan song.

"It's about what's actually right for the show, to be honest, and that has to be judged very carefully," he told the publication. "Think about the very limited but classic British output of certain shows, and there aren't that many of them."

However, it looks like co-creators Moffat and Gatiss have other things in mind. Parent Herald points out that the two have said in past interviews that they are already playing with ideas for "Sherlock" season 5.

With Cumberbatch's stance, could BBC and the co-creators continue the series without their main actor? Will "Sherlock" survive without Cumberbatch? That much is up for discussion.

"Sherlock" season 4 is expected to premiere in January 2017.