Spooky is the most neglected of the five basic human emotions: spooky, joy, sorrow, grouchy, and wet. Get horror glands pumping with today’s Groupon: for $30, you get two R.I.P. tickets (a $20 value each) and two photos (a $10 value each) aboard the USS Nightmare (a $60 total value), available on the following dates:

• Wednesday, September 28
• Wednesday, October 5
• Wednesday, October 12
• Wednesday, October 19
• Wednesday, October 26

The gruesome collections of ex-captain William S. Mitchell and actors possessed of perished sailors' spirits entice thrill seekers to a night of hair-raising fun aboard the USS Nightmare, which Hauntworld.com featured as one of the country's Best Haunted Attractions. After flashing their R.I.P. passes and skipping to the front of the lines—the last joyful thing they'll do before plunging into the depths of riverboat horror—brave guests wander the haunted halls, exploring the dreaded depths of the old riverboat's history and the 112 crewmembers lost during its decades of active service on the Missouri river. Inside the Queen's Chamber, courageous souls dodge ancient curses cast upon them by heaps of Egyptian antiquities, and even entomologists pale at the sight of the exotic and otherworldly creatures that line the walls and display cases of Insects of the World. Shrunken heads and tribal relics shock even the most hard-hearted explorers inside the Dark Arts and Freaks of Nature exhibit. The Dredge Spoils room displays the loot of decades of dredging, such as coins, bones, and old keys, while the Mitchell Laboratory frightens the mind with evidence of the captain's attempts to create life using the boat's steam power. To capture looks of terror and badly hidden pants-wetting forever, the experience includes a pair of souvenir photos.