While accompanying Pete's inventor grandfather to New York where the old man plans to sell his new invention, the Three Investigators find themselves in the middle of a dangerous spy case.
Something is fishy in Mermaid Court!First a little boy mysteriously vanishes, then a treasured statue of a mermaid disappears. An actor tells outrageous lies...a dog lover gets an unexplained bite...and lights flicker in the windows of the haunted Mermaid
When an ornery book collector disappears, the Three Investigators break into his secret computer files in search of clues and gradually uncover his mysterious past.