Actress Phyllida Moon, whose day job is PI at the Peter Piper Detective Agency in Seaminster, should have been off pursuing her love life in Scotland - but a gall bladder operation put an end to that. Her forced period of convalescence turns out to be too good an opportunity for DCS Kendrick to miss. Though he's only accepted Phyllida's help grudgingly in the past, he finds he just can't do without her. There have been a series of suspiciously premature heart attacks at Stansfield Manor Nursing Home and he appeals to Phyllida to investigate as a patient - real and undercover all at once. Phyllida, who has only ever investigated in disguise before, now faces the peculiar challenge of having to act herself.