Mrs. Carolyn Muir rents charming Maine Gull Cottage for her family and finds that it comes with a resident ghost. Captain Gregg takes a shine to the pretty widow and allows them to stay in his house.
Vanessa Peekskill, the great-great-granddaughter of Captain Gregg's true love, comes to Gull Cottage to research their romance, and the Captain is quite taken with her.
Carolyn comes down with a bug, and Captain Gregg, dissatisfied with the doctor, concocts his own remedy which sends Mrs. Muir back to the mid-1800's where she is the "ghost" and the very much alive Captain is the only one who can see her.
Thanks to Cousin Harriet's gossip, Carolyn's parents get the idea that the Captain is a real man that their daughter is seeing and come for a visit wanting to meet him.
Mrs. Muir needs money to fix the plumbing and can't come up with a single idea for an article, so the Captain collaborates with her on a story, but his secret revisions start giving people the wrong idea about her.
After an appeal to the vanity of their landlord doesn't work to get needed repairs made, the Captain sends him on a treasure hunt in the very areas that require fixing.