LYN MacPherson is a woman of mystery.
The former market research worker heads a UK-wide army of mystery shoppers - the people who test out the standards of service offered to customers in places like hotels, restaurants and even funeral parlours.
And demand for their "covert" activities is growing - as companies seek to compete by continually improving customer care.
Lyn set up MacPherson Mystery Shopper and Research Ltd two years ago and operates from the aptly-named Mystery House at her Cowlersley home.
The business, run by Lyn and her husband, Barry, draws on the efforts of 10,000 mystery shoppers overseen by 12 regional managers.
The mystery shoppers come from all ages and backgrounds - including unemployed people, young professionals, police officers, housewives and retired couples.
MacPherson Mystery Shopping carries out work for companies ranging from hair salons and restaurants to garages and banks.
Its clients also include opticians, publicans, funeral directors and operators of cinemas and golf courses.
Lyn said companies used mystery shoppers to assess the performance of staff dealing directly with the public - to make sure that the things staff learn in training is followed through in practice.
Said Lyn: "Mystery shopping is extremely big business in America, but there are not too many companies offering the service in this country.
"We have found a niche in a growing market."
But she stressed: "It is not a witch hunt. We are not here to point the finger at individual members of staff.
"The idea of mystery shoppers is to pinpoint areas for improvement in staff training.
"It may show that certain staff have poor product knowledge or it may highlight poor communications between departments in an organisation.
"Everyone has an off-day, so companies should carry out mystery shopping on a regular basis - not as a one-off - to monitor staff performances and find ways to improve."
Lyn set up the business two years ago after 17 years in market research.
She began by carrying a clipboard and quizzing town centre shoppers before becoming a field worker for an international market research company.
She branched out on her own after a contact in America asked her to "mystery shop" a chain of video stores.
The company has also drawn on the services of Business Link for West Yorkshire to help its growth.
Business Link adviser Henry Mooney has helped the company secure additional finance and expand to take on four full-time staff at its Cowlersley base.
And Lyn is also busy in the local business community.
She chairs the Kirklees committee of the newly-formed West Riding Region of the Federation of Small Businesses.