On a seemingly idyllic summer day, John and Bob’s fishing excursion takes a chilling turn when they reel in an unidentifiable, slimy creature from the depths of the local river. Against better judgment, they bring their catch home, unaware of the impending doom it heralds. Only Grandma, often dismissed as eccentric, senses the lurking danger. But her warnings fall on deaf ears.

As the situation spirals, it becomes clear that the creature is not alone. It’s communicating with another malevolent being, hell-bent on erasing John Catchpole from existence. In desperation, Grandma enlists the expertise of her trusted friend, Ruby Cartwright, a renowned figure in the paranormal realm. Together, they unravel a sinister plot, leading them to a final showdown with the dreaded Sylvia Slimehair. The stakes are high: banish Sylvia to the abyss or lose John forever.