It's the Orstra Project.. .not spelled correctly, sorry, but anyway, it's a Buffy/ Nikita crossover. Buffy and Spike are Kidnapped by Section 1 and are locked up. Buffy mystically becomes pregnant, Nikita and Michael arrange an escape for Buffy and Spike. I think this is what you are looking for. Hope so anyway, even if I couldn't spell it properly
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