In “Treason,” the main of MI6 is poisoned at a holiday getaway get together, and Deputy Chief Adam Lawrence (Charlie Cox) normally takes in excess of though he is recuperating. But it turns out the complete plan has been established in movement by Adam’s ex-girlfriend, a Russian spy, and she blackmails him into aiding her. Meanwhile, both MI6 and the CIA are on his scenario as he tries to get out from below this tangled web. His complex tale unfolds above the class of five episodes.