Maggie McKeown

Maggie McKeown is the deuteragonist of 1978 survival horror film, Piranha. She was portrayed by Heather Menzies.

Biography
Maggie is a private investigator. She searches for the missing teenagers and she teams up with Paul Grogan to find them, because of his knowledge about the place where they disappeared.

When Maggie finds out the missing teenagers were at an abandoned military test site, she, through her enthusiasm in finding them and because of a lack of respect regarding rules and other people's homes, unwittingly caused the Piranha disaster by emptying the place that was full of Piranhas against Grogan's objections in an attempt to find them there, sending them by doing that into the river.

As a coronation, Maggie did that without judicial permission. During this event Dr. Robert Hoak tried to stop her, but was knocked out by both of them. After she and Paul find out about the piranhas the next day through Dr. Robert Hoak, who regained his consciousness in the meantime, they, for the rest of the movie, do everything they can to limit the damage they caused by having to fight unbelievers and also the military, who want to cover everything up while also ignoring the risks of that to the extent that they even ignore the fact that the piranhas Hoak developed were intelligent and therefore; capable to overcome an obstacle regarding a dam by swimming through a secondary river.

They succeed in the nick of time by reaching the end of the river in the nick of time while having to see all those who die because of the fish. During this event she also meets Grogan's daughter, Susie. Once there they release pure poison into the water that was stored in a factory there underwater. This poison presumably kills all the piranhas.

After that Maggie tends the wounds of Paul that were caused by the piranhas, when he released this poison into the river with her help. This happens in the presence of his daughter in a place full of wounded people because of the piranha's actions. It is also implied, that she will face consequences regarding her indirect role in releasing the piranhas.

Trivia

 * Maggie (along with Paul Grogan) is indirectly responsible for releasing the piranhas, which led to several people being wounded or killed because of her indirect actions.