'Orphan Black' season 4 spoilers: Clone dies, Cal comes back; Helena gives birth in season finale?

The season 4 finale of the award-winning sci-fi series "Orphan Black" will air this Thursday, June 16.

According to various reports, the upcoming finale, which marks the end of what may be the show's penultimate season, could see the death of a clone, the return of Cal (Michiel Huisman), and Helena (Tatiana Maslany) giving birth in a yurt.

In its fourth season, "Orphan Black" has followed clones Sarah, Cosima, and Allison (all played by Maslany) as they search for a cure to the chromosomal abnormality that is putting their lives in danger.

The show's previous episode, titled "The Mitigation of Competition," showed Sarah and Rachel (Maslany) working together, Rachel taking down Evie Cho (Jessalyn Wanlim), and Cosima and Susan (Rosemary Dunsmore) butting heads over the ethical consequences of experimenting on humans.

With just one episode left and with the show's final act about to begin, TV Guide suggests that it is time for the series to kill off one of the clones.

According to the website, a clone death would bring the sisters together against the show's big Neolution threat and set the stage for the remaining clones to take the offensive in season 5.

Apart from the possibility of a clone death in the "Orphan Black" season 4 finale, Inverse suggests that audiences could find Cal returning and reconnecting romantically with Sarah. It could also show the clones coming together for the birth of Helena's twins.

In an interview with Peter Travers on ABC News' "Popcorn with Peter Travers," Maslany spoke about the challenge of playing more than a dozen roles on "Orphan Black."

According to the "Orphan Black" star, while she was initially daunted by the task, it has also been fun getting to portray so many different personalities.

"I think, for me, it's the most natural thing an actor can do, is transform like this," she said. "I think that's we're born to do. At least the people I admire and the people I work with, we are thrilled to get to transform, and we're excited by that challenge."

The "Orphan Black" season 4 finale will air on Thursday, June 16, at 10 p.m. ET on BBC America.