Claymore brings a stranger to look at the house who claims he is a student of architecture and wants to take photos of the house. When he comes back to the house after the Muirs leave for the evening Captain Gregg thinks he's a burglar and tries to scare him away, not realizing that he is actually a parapsychologist who is determined to find the ghost of Gull Cottage and make him known to an unsuspecting public.

The local historical society wants to erect a statue of legendary local Navy hero Captain Figg. Captain Gregg is insulted that he wasn't chosen and wants Mrs. Muir to expose Figg as the coward he was, but Mrs. Muir must have proof.

Prompted by her family doctor, Carolyn sees a psychiatrist, who convinces her that the Captain is a delusion she should ignore. When the psychiatrist shows up at Gull Cottage, the Captain takes delusion into his own hands.

Carolyn's distraught friend Aggie comes to visit after breaking up with her fiancé. Carolyn and the Captain set her up with Claymore.

Jonathan's history essay wins first place, but when he changes the essay to reflect facts the Captain provides, he stirs up resentment and puts his prize and the family's peace in jeopardy.

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.

The kids decide that they should have a surprise birthday party for Captain Gregg, but it is very difficult to keep their plans secret from him.

The Keystone Cops meet the Schooner Bay Fire Department via Claymore's misspending of civic funds. Carolyn does her due diligence to bring the department into the 20th Century.