A Guest + a Host = a Ghost

Not until three years after the death of her husband Jolly, Kay dares to move back into their former home, persuaded by her new fiancée Rupert. But soon her worst expectations come true, when not only her old memories haunt her, but also Jolly's ghost, who doesn't approve of her new mate. Invisible to anyone but Kay, he tries to prevent the wedding.

After being hypnotized by his sister-in-law, Tom Witzky begins seeing haunting visions of a girl's ghost and a mystery begins to unfold around her.

Recently deceased, a white-sheeted ghost returns to his suburban home to console his bereft wife, only to find that in his spectral state he has become unstuck in time, forced to watch passively as the life he knew and the woman he loves slowly slip away.

Mystery Inc. withdraws from solving crimes after botching a case. When Vincent Van Ghoul contacts the gang about an unfinished investigation from Daphne, Shaggy and Scooby's past, the gang springs into action to finish the job that involves catching the 13th Ghost that escaped from the Chest of Demons and is still at large.