The trials and tribulations of Orphan Black's Ledas and Castors will remain inextricably linked as season 4 begins.

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Tatiana Maslany's sestras have, by and large, been dealt the lion's share of the story. Although the Castor's have been all but decimated (we think), Mark's (Ari Millen) tale will continue to twist in and out of Sarah's when Orphan Black returns this spring.

"We're not finished with our male clones," executive producer Graeme Manson told TV Line. "Mark's still out there, and Ari Millen's still in the cast for Season 4, I guarantee."

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As the Clone Club probes the depths of their mysterious past, their cure could bring hope to Mark as well.

"If we can find our own cure, can we cure Mark? Is that a possibility for next season?" Manson teased. "Is Mark the one brother who's earned the right to call himself a brother?"

Fans should keep in mind that the creators have always had a definitive end point for the series. All these twist will eventually provide an answer to the overarching mystery, according to Deadline.

Orphan Black will return to BBC America in April. Check out the season 4 teaser trailer below.

Tags: Orphan Black television BBC America