Would you sign up to a medical trial if you didn't know the possible side effects?

18-40? PAID CLINICAL TRIAL IN THE CANARY ISLANDS - UP TO GBP20,000 TAX FREE

It seems like the opportunity of a lifetime. An all-inclusive luxury trip abroad, all you need to do is take a pill every day and keep a diary.

Except you don't know anything about the drug or what its side effects might be.

The headaches start, a dull ache at first. Every day worse than the last.

Then a body is found.

Everyone is a suspect. Anyone could be a killer. Even you . . .