Complex sentence: During this time, Imriel is asked to see Claude de Monluc, the captain of Sidonie's guard, who was worried that Imriel might be after his post.
Split into simpler sentences: During this time, Imriel is asked to see Claude de Monluc, the captain of Sidonie's guard. It appears that Claude de Monluc is worried that Imriel might be after his post.