You're closest to God when you're in the garden, right? Or are you close to something a little more alien?

Principal Rosa Di Natalia knew she needed some help to get her school's finances out of the red. The plants found by the girls on their science walk look to be sent from heaven – they truly are amazing plants, able to be whatever is needed, producing food and removing waste. And not just food either.

But Rosa can't help wondering what the ulterior motive is. After all, nothing is given for nothing. What do the plants want in return? And can she rescue the school, the town, the world from these very useful plants before it's too late?