My Brother, My Enemy (Star Wars: Rebellion, Vol. 1)

Having rescued Rebel strategist Jorin Sol from the Empire, Luke Skywalker now leads X-Wing attack runs on Imperial convoys to rustle up much needed supplies for the Rebel fleet. Little does he know that within Sol lies a secret that will put the entire Alliance in danger. What's worse, when Luke receives a coded message from Lt. Sunber, he must decide whether to trust his old friend or obey the orders of Princess Leia who believes Tank may be part of an Imperial plot to capture the Rebellion's greatest hero!