Malus hasn't heard from Willow since she walked out on him without explanation eight years ago. Unlike the majority of the population who would totally blow off such a letter, Malus confirms his loser status by flying up there at his own expense.
Malus bribes a pilot to take him to Summersisle, which turns out to be a an island inhabited by a strange beekeeping cult of women. Disturbing enough on it's own that he is stuck on this island full of women who don't like outsiders (especially men) until the supply copter comes back, but he also has a deadly bee allergy. How convenient to end up on Bee Island.
The island colony is run by Sister Summersisle. The school teaches that women are superior to men, and men are idiots whose only usefulness is breeding. Yes, Detective Malus ought to be really effective at investigating Rowan's disappearance.
When he starts his inquiries, he is told conflicting stories. One is that Willow never had a child. The other is that her child died. Willow insists that both are lies. In the course of tracking down the real story, Malus manages to get locked in an underground water tunnel, bumps into a beehive, and runs into a field of hives while being chased by a swarm. Malus turns out to confirm the teachings of the island as he is quite the idiot.
Malus only brings one suit, yet it is always clean, and his version of emotion is yelling. Then the ending is one of those "six months later" type of endings that will make you say aaarggh!! This is one terrible film.