Professor Branestawm is back! When Lady Pagwell (Diana Rigg) leaves a substantial sum to fund local inventing, it could mean the end of Branestawm's money troubles. But scheming local councillor, Harold Haggerstone (David Mitchell) has other ideas, and hires a rival inventor, the evil Professor Algebrain (Steve Pemberton) to steal the cash and drive Branestawm out of business. Also returning in this brand new adventure are Madeline Holliday as Connie, Sophie Thompson as Connie's mum, Vicki Pepperdine as Mrs Flittersnoop, Simon Day as Colonel Dedshott, Adrian Scarborough as the vicar, Jason Forbes as PC Peasey, Doreen Ingleton as Miss Silt and Charlie Higson as the mayor.