Island of Terror! is the name of the comic strip featured in issue 138 (final issue).
ln the opening pages, Dr X, along with a small army of X Robots, steals four prototype rocket engines from a testing facility in Nevada. The next moring, Action Force are at the scene. Action Man orders Redwolf and Flint to go back to base while Action Man takes care of things. He then sets of for Island X in his Air Assault helicopter. When he gets to the island, he spots a "new kind of Death Ray" in X City while he is fighting off some X Jets. From the controll centre, Dr.X shoots Air Assault with a Magna-Pulse Phaser in order to bring Action Man down. He survives the crash but then has to escape from a small X Robot army and get to the control centre. Dr.X then orders No-Face to begin take-off and it becomes apparent that his plan is to turn the hole of Island X into a "Satellite of Terror". Action Man then breaks into the control room but Dr.X soon punches him out of the window which he smashed through. Action Man then finds that Air Assault is still operational despite being a little shakey. Action Man then fires away at one of the with all he's got. Island X is then brought crashing down into the sea. Dr.X and No-Face are seen clinging on to part of the island as it sinks. However, their final fate is un-known. Action Man then meets up with Action Force and states that he thinks it's time for a holiday!