<p>The eighth season of the British spy series &quot;MI-5,&quot; which follows secret agents as they foil evil plots around the globe, begins with the fallout from Harry&#39;s kidnapping by the Russians. A mysterious organization known only as &quot;Nightingale&quot; is the ongoing focus of the eight episodes. And Lucas&#39; relationship with CIA agent Sarah Caulfied (Genevieve O&#39;Reilly), reignites concerns ...</p>