The Demon's Den (1984)
by Franklin W. Dixon
(#81 in The Hardy Boys)

The Demon's Den

The Hardy boys, vacationing in Vermont, offer to help the police locate a missing camper and find themselves involved with a doomsday cult, a deadly strain of bacteria, and possibly the devil.

Published:

1984

Genres:

Fiction / Mystery / Young Adult ... More genres

ISBN:

0006921825

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The Hardy Boys series
(190 books)

The Tower Treasure — #1 The Tower Treasure (1927)

The House on the Cliff — #2 The House on the Cliff (1927)

The Secret of the Old Mill — #3 The Secret of the Old Mill (1927)

The Missing Chums — #4 The Missing Chums (1928)

Hunting for Hidden Gold — #5 Hunting for Hidden Gold (1928)

The Shore Road Mystery — #6 The Shore Road Mystery (1928)

The Secret of the Caves — #7 The Secret of the Caves (1929)

The Mystery of Cabin Island — #8 The Mystery of Cabin Island (1929)

The Great Airport Mystery — #9 The Great Airport Mystery (1930)

What Happened at Midnight — #10 What Happened at Midnight (1931)

While the Clock Ticked — #11 While the Clock Ticked (1932)

Footprints Under the Window — #12 Footprints Under the Window (1933)

The Mark on the Door — #13 The Mark on the Door (1934)

The Hidden Harbor Mystery — #14 The Hidden Harbor Mystery (1935)

The Sinister Sign Post — #15 The Sinister Sign Post (1936)

A Figure in Hiding — #16 A Figure in Hiding (1937)

The Secret Warning — #17 The Secret Warning (1938)

The Twisted Claw — #18 The Twisted Claw (1939)

The Disappearing Floor — #19 The Disappearing Floor (1940)

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The Melted Coins — #23 The Melted Coins (1944)

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The Phantom Freighter — #26 The Phantom Freighter (1947)

The Secret of Skull Mountain — #27 The Secret of Skull Mountain (1948)

The Sign of the Crooked Arrow — #28 The Sign of the Crooked Arrow (1949)

The Secret of the Lost Tunnel — #29 The Secret of the Lost Tunnel (1950)

The Wailing Siren Mystery — #30 The Wailing Siren Mystery (1951)

The Secret of Wildcat Swamp — #31 The Secret of Wildcat Swamp (1952)

The Crisscross Shadow — #32 The Crisscross Shadow (1953)

The Yellow Feather Mystery — #33 The Yellow Feather Mystery (1953)

The Hooded Hawk Mystery — #34 The Hooded Hawk Mystery (1954)

The Clue in the Embers — #35 The Clue in the Embers (1955)

The Secret of Pirates' Hill — #36 The Secret of Pirates' Hill (1956)

The Ghost at Skeleton Rock — #37 The Ghost at Skeleton Rock (1957)

Mystery at Devil's Paw — #38 Mystery at Devil's Paw (1959)

The Mystery of the Chinese Junk — #39 The Mystery of the Chinese Junk (1959)

Mystery of the Desert Giant — #40 Mystery of the Desert Giant (1960)

The Clue of the Screeching Owl — #41 The Clue of the Screeching Owl (1962)

The Viking Symbol Mystery — #42 The Viking Symbol Mystery (1962)

The Mystery of the Aztec Warrior — #43 The Mystery of the Aztec Warrior (1964)

The Haunted Fort — #44 The Haunted Fort (1964)

The Mystery of the Spiral Bridge — #45 The Mystery of the Spiral Bridge (1965)

The Secret Agent on Flight 101 — #46 The Secret Agent on Flight 101 (1967)

Mystery of the Whale Tattoo — #47 Mystery of the Whale Tattoo (1967)

The Arctic Patrol Mystery — #48 The Arctic Patrol Mystery (1969)

The Bombay Boomerang — #49 The Bombay Boomerang (1970)

Danger on Vampire Trail — #50 Danger on Vampire Trail (1971)

The Masked Monkey — #51 The Masked Monkey (1972)

The Shattered Helmet — #52 The Shattered Helmet (1973)

The Clue of the Hissing Serpent — #53 The Clue of the Hissing Serpent (1974)

The Mysterious Caravan — #54 The Mysterious Caravan (1975)

The Witchmaster's Key — #55 The Witchmaster's Key (1975)

The Jungle Pyramid — #56 The Jungle Pyramid (1976)

The Firebird Rocket — #57 The Firebird Rocket (1978)

The Sting of the Scorpion — #58 The Sting of the Scorpion (1978)

Night of the Werewolf — #59 Night of the Werewolf (2005)

Mystery of the Samurai Sword — #60 Mystery of the Samurai Sword (1979)

The Pentagon Spy — #61 The Pentagon Spy (1980)

The Apeman's Secret — #62 The Apeman's Secret (1980)

The Mummy Case — #63 The Mummy Case (1980)

Mystery of Smugglers Cove — #64 Mystery of Smugglers Cove (2005)

The Stone Idol — #65 The Stone Idol (1981)

The Vanishing Thieves — #66 The Vanishing Thieves (1980)

The Outlaw's Silver — #67 The Outlaw's Silver (1981)

The Submarine Caper — #68 The Submarine Caper (1981)

The Four-Headed Dragon — #69 The Four-Headed Dragon (1981)

The Infinity Clue — #70 The Infinity Clue (1981)

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The Voodoo Plot — #72 The Voodoo Plot (1982)

The Billion Dollar Ransom — #73 The Billion Dollar Ransom (1982)

Tic-Tac-Terror — #74 Tic-Tac-Terror (1984)

Trapped at Sea — #75 Trapped at Sea (1982)

Game Plan for Disaster — #76 Game Plan for Disaster (1982)

The Crimson Flame — #77 The Crimson Flame (1981)

Cave-In — #78 Cave-In (1983)

Sky Sabotage — #79 Sky Sabotage (1983)

The Roaring River Mystery — #80 The Roaring River Mystery (1984)

The Demon's Den — #81 The Demon's Den (1984)

The Blackwing Puzzle — #82 The Blackwing Puzzle (1984)

The Swamp Monster — #83 The Swamp Monster (1985)

Revenge of the Desert Phantom — #84 Revenge of the Desert Phantom (1985)

The Skyfire Puzzle — #85 The Skyfire Puzzle (1985)

The Mystery of the Silver Star — #86 The Mystery of the Silver Star (1987)

Program for Destruction — #87 Program for Destruction (1987)

Tricky Business — #88 Tricky Business (1988)

Sky Blue Frame — #89 Sky Blue Frame (1988)

Danger on the Diamond — #90 Danger on the Diamond (1993)

Shield of Fear — #91 Shield of Fear (1988)

The Shadow Killers — #92 The Shadow Killers (1988)

The Serpent's Tooth Mystery — #93 The Serpent's Tooth Mystery (1988)

Breakdown in Axeblade — #94 Breakdown in Axeblade (1989)

Danger on the Air — #95 Danger on the Air (1989)

Wipeout — #96 Wipeout (1989)

Cast of Criminals — #97 Cast of Criminals (1989)

Spark of Suspicion — #98 Spark of Suspicion (1993)

Dungeon of Doom — #99 Dungeon of Doom (1989)

The Secret of the Island Treasure — #100 The Secret of the Island Treasure (1990)

The Money Hunt — #101 The Money Hunt (1990)

Terminal Shock — #102 Terminal Shock (1990)

The Million Dollar Nightmare — #103 The Million Dollar Nightmare (1990)

Tricks of the Trade — #104 Tricks of the Trade (1990)

Smoke Screen Mystery — #105 Smoke Screen Mystery (1990)

Attack of the Video Villains — #106 Attack of the Video Villains (1991)

Panic on Gull Island — #107 Panic on Gull Island (1991)

Fear on Wheels — #108 Fear on Wheels (1991)

The Prime-Time Crime — #109 The Prime-Time Crime (1991)

The Secret of Sigma Seven — #110 The Secret of Sigma Seven (1991)

Three-Ring Terror — #111 Three-Ring Terror (1991)

Demolition Mission — #112 Demolition Mission (1992)

Radical Moves — #113 Radical Moves (1992)

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Racing to Disaster — #126 Racing to Disaster (1994)

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The Crisscross Crime — #150 The Crisscross Crime (1998)

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Danger in the Extreme — #152 Danger in the Extreme (1998)

Eye on Crime — #153 Eye on Crime (1998)

The Caribbean Cruise Caper — #154 The Caribbean Cruise Caper (1999)

The Hunt for the Four Brothers — #155 The Hunt for the Four Brothers (1999)

A Will to Survive — #156 A Will to Survive (1999)

The Lure of the Italian Treasure — #157 The Lure of the Italian Treasure (1999)

The London Deception — #158 The London Deception (1999)

Daredevils — #159 Daredevils (2000)

A Game Called Chaos — #160 A Game Called Chaos (2000)

Training for Trouble — #161 Training for Trouble (2000)

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Skin & Bones — #164 Skin & Bones (2000)

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Past and Present Danger — #166 Past and Present Danger (2001)

Trouble Times Two — #167 Trouble Times Two (2001)

The Castle Conundrum — #168 The Castle Conundrum (2001)

Ghost of a Chance — #169 Ghost of a Chance (2001)

Kickoff to Danger — #170 Kickoff to Danger (2001)

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Speed Times Five — #173 Speed Times Five (2002)

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