Series title: Health of Strangers
The Health Enforcement Team are back, the threat of mutant influenza still plaguing the streets of Edinburgh.
When Scotland's leading virologist doesn't attend his mandatory health check mere days before his presentation to the Scottish Parliament, Mona and Paterson scramble to London to track him down. Meanwhile, Bernard's search for a missing young woman using a fake identity leads him deeper into Edinburgh's dark underworld than he had planned.