The Lights Over Cromer

Strange lights in the sky over the Norfolk coast.
A shortage of crab-meat sandwiches.
And Mr Gordon Drooko, umbrella magnate, launching himself into the air wearing only a knitted bathing-costume and a pair of mechanical wings.
Petticoat Katie - peppermint cream aficionado and Fortean investigator - and her substantial friend Sledgehammer Girl (bicycle technician to idle gentlefolk) just can't leave this to amateurs.

Also features half a pork pie and a rowing-boat.