Talk:Lightning Tower/@comment-11113283-20130621043128/@comment-4632427-20130730070453

I couldn't tell you when this is unlocked, since I don't generally build base defenses. I'm also not quite sure what mission you're talking about with the "Invading sandworms bait," but that sounds like a mission from far earlier in the game than is usually dealt with at level 55. Odds are, when you complete it, you'll unlock more missions to do.