Martin rubs up against the new herbalist and Penhale, Louisa and James are all interested in Janice's new pedicure fish. Martin advises Mrs Irene Moore (Lesley Nicol) to stop cold-water swimming until they've ruled out the cause of her migraines. Martin's ex-flame invites him to speak as keynote speaker at Imperial College, and Ruth is back from Mexico with more than maracas.
