At the beginning of your turn, if the Hellcannon is not in combat, take a LD test. If the test is failed, the Hellcannon to is then subject to Random Movement (3D6) until the beginning of the next turn, and must move towards the nearest enemy unit. If the Hellcannon would get destroyed as a result of it being Unstable, treat this as rolling a 1 on the Hellcannon misfire table.