The Hellcannon constantly strives to break free of its bonds. At the beginning of the turn, if the Hellcannon is not in combat, take a Leadership test for the unit. If it passes the test, the unit may behave as normal. If it fails the test, the unit will not fire and instead must make a compulsory move 3D6" towards the closest enemy unit. If the unit's movement is sufficient to take it into an enemy unit then it counts as charging. The target may make a charge response as normal, counting the Movement value rolled as the Hellcannon's maximum charge distance.