Elementary sneak peek: Meet Shinwell Johnson

Sherlock and Watson will have a new ally of sorts when Elementary returns.

True Blood star Nelsan Ellis joins the show as reformed criminal and Sir Arthur Conan Doyle character Shinwell Johnson — and EW has an exclusive first look at his debut.

Fearing Joan’s professional wanderlust, Sherlock encourages Joan to assist Shinwell after they cross paths on a case. Shinwell, who is transitioning out of jail, is a former patient of Joan’s from when she was a surgeon.

“He is someone with a dark and troubled past, who is trying to reform himself, but he brings a lot of baggage to our doorstep,” executive producer Rob Doherty recently told EW, noting that as Joan and Sherlock come to learn more about Johnson, “there may be a difference of opinion on whether keeping him in their orbit is such a good idea.”

Elementary returns Sunday, Oct. 2 at 10 p.m. ET on CBS.