A blunt yet brilliant surgeon becomes the general practitioner in a quaint fishing village.

While Martin continues to struggle with his blood phobia, a mermaid washes ashore in Port Wenn to the amazement of everyone in town; a well-meaning townsperson creates havoc while on prescribed oxygen.

When the Port Wenn pharmacy is robbed, including Louisa's critical time-sensitive medicine, Martin deduces that the culprit desperately needs his help; Greg and George clash with a rival food truck owner; Sarah tries to bond with Eden; Martin is on the receiving end of a special brand of Port Wenn affection.

The citizens of Port Wenn get competitive during their annual floating crate race; Martin tries to give important medical advice when three men have positive pregnancy tests; former record-holder Sarah coaches Peter in the art of crate racing.

As Martin desperately tries to leave Port Wenn to meet Eden in Boston for the weekend, he must first investigate the extremely strange behavior of three patients who have all recently visited a meditation retreat; Mark is affected by the high school's graduation; Sarah's first guest in her rented spare room is none other than ex-paramour Eddie McCroy.

When the wife of a traveling magician duo dies at the Salty Breeze, Martin must help the husband who is unable to grasp that she is gone; Martin gets a new male medical monitor who has an instant connection to Louisa.

Martin works to debunk the sudden miraculous cures for the people of Port Wenn when self-proclaimed homeopath Savannah returns to town; Martin becomes acutely aware of Louisa and Parker's new connection.
Martin becomes concerned when during the Port Wenn Revolutionary War reenactment, some of the citizens start displaying tremors and odder-than-usual behavior; Martin is affected by Louisa's new relationship with Parker.
When he discovers that his predecessor, the beloved Dr. Reese, had diagnosed a patient's brain tumor moments before he died, Martin, with Louisa's help, must deduce who it was in order to save them.