He was 'complicit' in the cover-up. [=he helped with the cover-up]
(..) These are the sons of Ragnar Lothbrok. They want revenge for the death of their father. They killed Aelle. But they know your father was complicit in his death. So it seems inevitable that they are marching towards Wessex. I believe this man. I always thought they would seek revenge (..)2017 TvShow: Vikings Title: On the Eve Season: 4 Episode 19