The Fifth Room (writing as AJ Rushby)

When brilliant high-school student Miri is invited to join an international secret society, she leaves everything behind in pursuit of the high-stakes rewards it offers. In a secret bunker, four selected students are pitted against each other to push the boundaries of medicine using illegal self-experimentation. When Miri discovers her ex-boyfriend there as well, the pair must pretend they don’t know each other, or risk expulsion, or worse. When Miri uncovers the fact that another student is secretly experimenting alongside the others, suddenly the stakes are much higher, and much more dangerous. Miri is forced to question the true purpose of the society, and who lies behind it. Readings Dymocks Book Depository