As soon as I read the premise of this novel, a group of travelers stranded in a small hotel in New York's Catskill Mountains during a violent snowstorm, I instantly thought of Dame Agatha Christie. She was a master of the “locked-room” style of murder mystery done with precision in THE MOUSETRAP and AND THEN THERE WERE NONE. I don't believe this comparison was lost on author Shari Lapena as one of the characters in the inn is reading an Agatha Christie novel in the book’s early stages.

AN UNWANTED GUEST is a nice shout-out to Dame Agatha, and Lapena sets things up like a classic whodunit. She introduces the characters and then sets them in a circumstance from which they cannot immediately escape. When guests begin to turn up dead, one by one, it will be a mad scramble to identify who the unwanted guest is before everyone is doomed.

The story opens with a brief introduction of the characters staying at Mitchell's Inn. Much of the first night spent there finds them sizing each other up, swearing to themselves that a new face they see looks familiar, but unable to put their finger on it. However, there is no Wi-Fi or cell phone service at the inn, so there is no chance to Google the guest who seems so recognizable.

"AN UNWANTED GUEST is very much a modern-day telling of a classic Agatha Christie plotline that is masterfully designed. Lapena knows and respects this type of murder mystery, and the end result is a novel that demands to be read in one sitting..."

Let's run down the players --- or potential victims --- to see who we are working with. Gwen is up for a girlfriend's weekend with her best friend, Riley, who still suffers from PTSD that she brought back from her time as a war correspondent for the New York Times. Lauren and Ian are a happy couple off for a weekend getaway in the country. Beverly and her husband, Henry, are the oldest guests. Beverly is hoping to rekindle the romance in her dull marriage; Henry is looking for the best way to say goodbye. Dana and Matthew are a flashy young couple looking for some fun; Matthew comes from old New England money. Candice is a writer who may be using the weekend retreat as an opportunity to begin work on a new project. Lastly is David, a popular New York City defense attorney seeking some solace from his work.

Due to the violent snowstorm that began as the guests arrived on Friday evening, the staff is extremely limited. Mitchell's Inn is a family-run business, and the only two employees are James, the caretaker, and Bradley, his young son. James is manning the kitchen, while Bradley is doing other odd jobs like check-in and bartending. After getting drinks from Bradley and enjoying a small buffet, courtesy of James, most of the guests make their way to the expansive library. As they are perusing the various titles, Gwen states, “I love a good murder mystery.” How ironic since she will be a part of one herself.

Early the next morning, with the storm still raging and no power, some of the guests claim to have heard raised voices and a woman screaming. The body of Dana is found at the foot of the staircase. Further inspection shows that it was not the fall that killed her but the blow to the back of her head. David, as a defense attorney, takes charge, indicating the body should not be touched or moved until the police are called in. However, under the current weather conditions, no authorities will be heading their way any time soon. The morbid decision is made to leave Dana's body where it is and cover it with a sheet.

Matthew is initially suspected of killing his fiancée, which he vehemently denies. David encourages him to say nothing and seek good counsel when phones are available again. Many of the guests felt that they may have known some of the others’ faces upon their arrival, but no one could place where or when they might have seen or met them. Riley and Gwen, after hours of pondering, realize why they recognized David --- he had been famously accused of killing his own wife. Even though he was acquitted, the women are not feeling safe based on the fact that one of them has murdered Dana.

An unoccupied room is found in the inn with the bed unmade as if someone was sleeping there. James and Bradley assure their guests that no one was registered to that room --- but could it have been used by another, unwanted mystery guest who might also be a clever murderer? Suspicions soon fly around the remaining guests. As expected, others begin to perish one by one. Even having all of them sleep, or at the very least stand guard, overnight on Saturday in the entrance hall of the inn is not enough to keep the head count from diminishing. This killer is quite clever and continues to set up situations where he or she can isolate a member of the inn and finish him or her off.

I won't give away any more of the action. All I can say is that AN UNWANTED GUEST is very much a modern-day telling of a classic Agatha Christie plotline that is masterfully designed. Lapena knows and respects this type of murder mystery, and the end result is a novel that demands to be read in one sitting --- preferably not while you are staying at a quaint little inn or a bed and breakfast in the midst of a winter snowfall!