The show begins with Dr. Martin Ellingham getting a job in a tiny town on the Cornish coast--a far cry from his fancy work doing surgery in London. Why he does this isn't mentioned in this show and it becomes amply apparent in later shows. Unfortunately, Doc Martin's first days in the town go extremely poorly. Part of it is because of his brusque and nasty demeanor and part is because this is an awful little town. Regardless the two need to learn to work together. Another issue involves some guys with gynecomastia--a situation with the doctor clearly screws up royally.
Overall, this is a nice introduction to the series though very different from the three previous movie incarnations of Doc Martin. While Martin Clunys plays all these folks, the movie Doc Martin comes to the same town but is Doc Martin Bamford, not Doc Martin Ellingham. Odd-- especially since Doc Ellingham is a much nastier sort.
By the way, the title refers to a person losing their mind, or going 'bodmin'.