Based on the life of famous 1920s nightclub owner Kate Meyrick whose clubs were referred to in a newspaper article as shrines of gaiety.
Slightly disjointed narrative that seemed a bit hard to always follow but more often than not a very good read about a hectic post-WW1 London - full of over-privileged 'bright young things' and characters inhabiting a cruel underworld of crime and police corruption - but all basically traumatised by the most terrible of wars.
Oh, 'disjointed' is spot on. It is a trait of Atkinson's style. Sometimes with awesome results (such as Life After Life) and sometimes with average results (such as When Will There Be Good News).