HISTORICAL NOVELS are often given a second life by anniversaries of the events depicted and Pat Barker’s Regeneration, shortlisted for the Booker Prize in 1991, has cannily been adapted as a drama (co-produced by the Northampton theatres with the Touring Consortium Theatre Company) to mark the centenary of the start of the First World War. As the story also takes place mainly in Scotland, there was another topical frisson when the show opened in the run-up to the independence referendum. Admittedly, most of Barker’s characters – animated for the stage by Nicholas Wright – are accidentally (in various senses of the word) north of the border, in a location that has been chosen for a ­rehabilitation hospital mainly due to its ­reputation for recuperative lands