As "Game of Thrones" begins production for season 4, "Sherlock" actor, writer, and producer Mark Gatiss will join the series. But how will this affect "Sherlock" as it attempts to finish season 3?

Although "Sherlock" season 3 is expected to air later this year, filming is currently on hiatus as Martin Freeman goes back to New Zealand to shoot more of "The Hobbit."

"We've done two. But we've now got a small gap - a small gap? A large gap! - while Martin (Freeman) goes back to New Zealand to film a bit more of the 'Hobbit' and then he'll return to us," says "Sherlock" producer Steven Moffat during a recent interview with EW.

"Hopefully, by that time [Freeman's return], I'll actually have finished the 'Sherlock' script I'm writing and we'll make another one," says Moffat.

But with another episode left to script and film, how will Mark Gatiss juggle his roles, given that "Game of Thrones" is confirmed to be shooting right now?

As of now, Gatiss' "Game of Thrones" role is still unnamed, but hopefully the actor/producer can film for the prolific HBO series and simultaneously oversee "Sherlock" season 3.

As seen in the clip above, Gatiss also plays Sherlock's brother Mycroft, who is obviously featured in season 3. Perhaps the third episode, which is rumored to be titled "His Last Bow," will not feature Mycroft.

Only time will tell as both "Game of Thrones" and "Sherlock" continue their production schedules.