Moon Lee plays a secret agent who joins an assassins' organization in Thailand under cover. Her boss is a lady in black with a pet crocodile. When Moon's transmitter has to be left behind, she loses contact with the Iron Angels team. They don't seem to worry much about her, though. In the middle part of the film, Moon is not on screen for 30 minutes while her colleagues attend a somewhat distracting boxing championship. Fortunately, she returns with a great fight against countless enemies, and there is a bit more ammo spent later on, so the movie doesn't forget what it is about (girls'n'guns).
"Iron Angels 3" is not the best one of the trilogy. Part 1 had the best cast (including Yukari Oshima) and part 2 the best story. Part 3, also without Elaine Lui now, brings in new guys which are rather annoying: the young man assisting Fong and an American nerd called Computer (ouch). I voted 7/7/6 for the trilogy. Note: there is a movie marketed as "Iron Angels 4" in some countries, but that one is not connected to the Iron Angels trilogy, except that Moon Lee is accidentally in it, too. You'll find it under "Jin pai shi jie"/"Princess Madam" here.