“Despite the mysterious warning, the pretty teen-age detective and a group of friends start out on a ghost-hunting expedition to investigate five places reputed to be haunted. Danger strikes at once when Nancy tries to overtake the canoe that paddles itself on Lake Sevanee. Thrills and chills mount as the ghost hunters pursue a phantom horse and ghost rider racing across the field that surrounds the Red Barn Guesthouse. During these happenings and other weird events Nancy finds herself pitted against a dangerous adversary, clever enough to operate invisibly.

In a dramatic climax Nancy outwits her enemy in an eerie mansion and traps him in the fantastic Room of Skulls.”

The Invisible Intruder (Amazon) (Abebooks) is not your typical Nancy Drew mystery. Important to note that Helen Corning Archer is back with her husband Jim who invites Nancy and the gang to investigate hauntings and happenings at five different locations. Of course, for those that don’t remember, Helen was there at the beginning of the series, but wasn’t very helpful to Nancy, so she got married off and Bess and George appeared on the scene. There’s even a few other couples invited on this trip, making for a very large, completely unnecessary crowd.

The Invisible Intruder is also the first Nancy Drew books to use the words “cool” and “groovy” to make them accessible to the 1960’s contemporary audience. I thought it was kind of funny, but it definitely made me place this book into the right year (1969). And once again, the illustrations show Nancy in pants, wahoo. Which just goes to show you that Nancy Drew keeps up with times and isn’t stuck in the past.

“Nancy felt that this tall, good-looking boy was just about everything a girl could wish for. He was wonderful company, lots of fun, yet serious and practical whenever the young detective enlisted his aid on a case.” Wait, what? Nancy actually thinking about Ned as more than just heavy muscle when solving cases? First there was kissing in a book a few books back, and now this? Maybe it was “Carolyn Keene’s” way of showing Nancy as more human, with feelings about people instead of just mysteries.

Each of the phantoms turns out to be the same people, who want to buy popular inns and resorts below face value. How do they do that? They make the places appear haunted. In each case, Nancy and the gang quickly dispatch the truth to the inn keepers and head on to the next haunted resort.

In terms of peril, Ned is attacked by a giant octopus (which turns out to be a man in a suit) right after there’s a bit of an info dump about octopi. There’s also quite a bit of information on types of shells, and of course, while dealing with phantoms and intruders, Nancy also falls on to a mystery involving a stolen shell collection. And Nancy is hit by a small flaming rocket aimed in her direction. All pretty tame compared to some Nancy Drew books.

I never really liked the cover of the Invisible Intruder. The ghost/sting ray wasn’t really eerie to me, more funny-looking than anything.

For my Nancy Drew book reviews, click here.

For more information about my favorite sleuth, check out Jenn Fisher’s Unofficial Nancy Drew website, which has a wealth of information.

For more information on series books, Jennifer White has a fabulous website that you can visit by clicking here.

For more of my book reviews, visit www.bargain-sleuth.com

Or subscribe below and never miss a review.

Join our Facebook page Bargain Sleuth Book Reviews or join our book group here.

This post contains affiliate links, meaning I may earn a few pennies for any purchases you make by clicking the links in this post. These monies are at no additional cost to you and help offset the cost of web hosting.