Martin struggles to deal with the news of Louisa's pregnancy. But Louisa is adamant that she does not want Martin involved. She is hired to teach at the local school, but the Headmaster is acting strangely. He has an arm that rises up into the air without him seeming to notice it! The Headmaster comes to see Martin about his constipation, but starts acting in a paranoid manner. Martin notices his strange physical behavior for the first time, but before he can complete his examination, the Headmaster rushes from the Surgery. At the hospital for a routine check-up, Louisa discovers that Edith is going to be her doctor. She also learns something about Martin and Edith's relationship during medical school that shocks her. Upon returning to school, Louisa discovers that the Headmaster has taken her pupils down to the treacherous rock pools of Roscarrock Cove for a nature walk. She alerts Martin and he rushes there to try and save the children.
Doc Martin: Uneasy Lies the Head, Thursday at 8 p.m. on PBS 6.