"Orphan Black" season 3 will explore more about Project Castor, which is a military operation of male clones.

Project Castor was introduced at the end of season 2 wherein Mark (Ari Millen) was revealed to be a clone.

However, another interesting story emerged, stating that Ari Millen was not originally intended to appear in "Orphan Black" season 3. At the panel during the recent San Diego Comic Con, it was revealed that show runners originally planned to kill off Mark in the sixth episode of the second season, but decided against it. Mark is claimed to play a major role in the third season.

Executive Producer and Co-creator Graeme Manson said that it was a great way to close the season to reveal Mark as a clone as no one would have guessed it. "We realized just from a pure storytelling point of view that the face that Sarah sees at the end is the same face that sits across from her at the diner in the opening sequence," Manson told TV Line.

Meanwhile, the third season of "Orphan Black" is reported to come back on air in the spring of 2015. Moreover, the filming of the next season just started that will surely bring forth a lot of spoilers.

Renewing the show for another season by BBC is not surprising after the successful run of the first and second season of the series. Moreover, the series proved to be one of the most successful series on television and has garnered international awards. According to reports, 10 episodes have been confirmed so far and Tatiana Maslany will still play the main character with multiple clones.

Main protagonist of the show, Tatiana Maslany, received a Golden Globe nomination and honors from the Critics' Choice TV Awards, TCA Awards and Canadian Screen Awards. Thus, it is not surprising that producers opted for another season of the series.