When a pharmacist accidentally prescribes poison instead of painkillers, the race is on to find the killer pills.

David Anthony, a Harley Street physician, swaps duties with his brother, a medical missionary in Africa.

Esther and her sister Jennifer have just taken a remote country cottage. But there is strange gossip about the previous occupants.

Following a group of five very different student nurses during their first year of training at an NHS hospital in London called St. Augustine’s...