Marty Sullivan owns a black cat named Edgar that mysteriously appears at the most unusual times and in the least expected places. For the others in Dee's Mystery Solvers Club, they suspect the cat is somehow magical. However, Marty has a nagging secret he wishes to tell the other club members about where he found Edgar. After he reveals his secret, he knows that Dee, his adventurous sleuthing sister, won't rest until they solve the mystery. Her stubbornness to find the truth will put their lives into peril, especially when she learns he found Edgar in the haunted Tangled Forest. Marty's greatest fear is that returning to the forest might cause him to lose Edgar forever, as the cat's true owner is a ghost ... The ghost of a witch.