The Fifth Room by Allison Rushby

Scholastic, 2017. ISBN 9781742762548
(Age: 12+) Recommended. Themes: Science, Self experimentation, Ethics, Secrets. Miri is asked to join a secret society which offers four students the chance to self-experiment in order to push the boundaries of medical research. When Miri discovers her boyfriend Sheen is also a member of the group she must hide the fact that she knows him, and when she uncovers the fact that there is a fifth student, one she doesn't trust, experimenting in the fifth room at the bunker, she begins to question just what is going on. Then things begin to get out of hand and the group members have to decide how far they will go with the experiments, and some are willing to go further than others.
This is a very different plot to the one that I was expecting, and I found it very intriguing. I was fascinated by the notion of scientists experimenting on themselves to find out the limits of medicine and willingly followed the experiments of the four students as they put their theories to the test. The competition between the students brings out the worst in some of them as they battle for the large cash prize and status of having the best experiment. The four characters are highly intelligent and competitive and must make some difficult decisions about medical ethics. Miri narrates the story in the first person and the tension builds to a dramatic climax and some very unexpected twists and turns.  
As well as a tense plot, Rushby has created believable characters who have to examine their own motivations and work out how far they are prepared to go to achieve fame and money in their scientific field. Miri's relationships with her father and her best friend are good and her feelings for Sheen, a most likeable young man, add a touch of romance to the story.
This was a very readable psychological thriller which will appeal to any student who likes an unusual and gripping plot and characters that might not be trusted.
Pat Pledger