Nancy travels to Ireland to be the maid of honor in her friend Kyler Malloy's wedding. As Nancy arrives, however, a ghostly figure runs out in front of her car causing her to crash. The caretaker, Donal Malloy, tries to send Nancy away saying the wedding has been called off. She soon finds out the groom is missing, and everyone has their own suspicion as to why. There have also been strange noises and lights around the castle, and even sightings of a banshee! Does the banshee's scream foretell the death of one of the castle's occupants? Has the groom really run off on his own as a practical joke, or did something more sinister occur?
As with all Nancy Drew games there is the potential for many fatal accidents, such as:
- Attempting to cross the bog and drowning.
- Exploding the jet pack.
- Trying to jump across the gap in the tower stairs and falling.
- Falling off a cliff.
- Plummeting into the ocean while using the jet pack.
- Mixing volatile chemicals and causing an explosion.
- Detonating a WWII-era rocket.
Kyler Mallory - A stock broker in London who lived with Nancy's family as an exchange student four years ago. She is now engaged to Matt Simmons and is excited to hold her wedding at Castle Malloy. Her grandfather, Edmund Malloy, recently died and named her as the sole beneficiary. He never spoke about his childhood and Kyler is just now learning about her true family history. Her real last name is actually Malloy, her grandfather changed it to Mallory so no one would find out they were Irish.
Matt Simmons - A travel and sailing free-lance writer for magazines. Known for his dry wit, Matt loves to play pranks on others. Friendly and likable, he had planned on getting married in the Bahamas, but agreed to change his plans to make his fiancée, Kyler Mallory, happy.
Kit Foley - Matt's best friend and accomplice on sailing trips. Kit was born in the US and is the son of a Krolmeister Inc. VP. The company transferred the family to London when Kit was young, but he never picked up the British accent. He currently works as a land developer, and he arrived early to help Matt and Kyler prepare for their wedding. He used to date Kyler, he is also the one who introduced Kyler to Matt.
Donal Delany - As Castle Malloy's ever-present caretaker, he's been watching the grounds for too many years to count. This Irish born gentleman isn't particularly fond of the British and he's the first to admit it. He is however the resident expert on Irish mythology and lore, which might explain his overly superstitious nature. He likes Kyler but hates Matt.
Alan Paine - Matt's best man and office mate who heard Kit and Matt arguing. He doesn't like to go to Castle Malloy any more until Matt has been found. You can only reach him through phone.
Seamus - The owner of The Screaming Banshee Inn. He is an unseen character but you can hear his voice when Nancy is making drinks.
Bess Marvin and George Fayne - Nancy's two best friends who got invited for a party.
Ned Nickerson - Nancy's boyfriend who also got invited to the party where Bess and George is. He is hiding from a girl who has a crush on him.
- Nancy Drew - Lani Minella
- Kyler Mallory - Alycia Delmore
- Donal Delany - Evan Mosher
- Kit Foley - Matthew C. Shimkus
- Matt Simmons - Peter Dylan O'Connor
- Ned Nickerson - Scott Carty
- Bess Marvin - Jennifer Pratt
- George Fayne - Patty Pomplun
- Seamus - Jonah Von Spreecken
- When creating the seating plan, some of the other guests are actually the names of characters from other Nancy Drew games. Jane and Linda are from Curse of Blackmoor Manor, Rose is from Message in a Haunted Mansion, Lori and John are from Last Train to Blue Moon Canyon, Heather is from Danger By Design, Taylor is from Secret of the Scarlet Hand, Henry is from Legend of the Crystal Skull, and Richard is from Secret of the Old Clock.
- When you look through the picture of Kit and Kyler by the fire place, the background is the Rialto Market, a place where Nancy can sell flowers in The Phantom of Venice.
- The teddy bear by the shelf at the nursery is like the one in the general store in Secret of the Old Clock.
- The glass eye on the vanity in the nursery was one of the twenty-five found in Legend of the Crystal Skull.
- The fortunes Nancy receives from the machine in the main hall make references to several other games. The first, "I see the sea in your future", is a sly hint at Ransom of the Seven Ships, the next Nancy Drew adventure. One reads "Fight the power!", a catchphrase from The Final Scene. Another says, "What card am I looking at?", which featured in a puzzle in Secret of the Old Clock. Another one reads "BALDO!", a name of the federal agent mentioned in Ghost Dogs of Moon Lake
- The sign inside the desk in the tower says Waverly Academy for Girls. Warnings at Waverly Academy is the twenty-first game and takes place at an all-girls school which several Nancy Drew characters went to.
- On the invitation, it gives the details as to whom is getting married, when, and where, but it does not say that they are getting married at all.
- The book Kyler is reading looks just like Marie Antionette's journal in Treasure in the Royal Tower.
When you are first talking to Kyler you hear her mention Togo the only reference we had of the dog since Nancy's voice on her home answering machine when you call home in The Haunted Carousel.
- Solving the fourth dollhouse puzzle by entering "LAPIN" from the book in the nursery into the roll-top desk
- Hitting four darts into the '50' section
- Twisting the summer pillar until you get a sheet of clovers that tell you to turn the leprechauns to either 12, 3, 6, or 9