It is 1928. Matilda Simpkin, rooting through a cupboard, comes across a small wooden club - an old possession of hers, unseen for more than a decade.

Mattie is a woman with a thrilling past and a chafingly uneventful present. During the Women's Suffrage Campaign she was a militant. Jailed five times, she marched, sang, gave speeches, smashed windows and heckled Winston Churchill, and nothing - nothing - since then has had the same depth, the same excitement.

Now in middle age, she is still looking for a fresh mould into which to pour her energies. Giving the wooden club a thoughtful twirl, she is struck by an idea - but what starts as a brilliantly idealistic plan to tackle the rising tide of pre-World War Two British fascism is derailed by a connection with Mattie's militant past, one which begins to threaten every principle that she stands for.