1x2 - Mystery of the Desert Giant / The Viking Symbol Mystery

September 13, 1969

1x3 - The Secret of the Old Mill / The Missing Chums

September 20, 1969

1x4 - The Secret Warning / The Mystery of the Aztec Warrior

September 27, 1969

When their nocturnal search of the Applegate property is suddenly interrupted, the Hardys learn more about the mysterious treasure---and discover that they're not the only ones looking for it. Applegate: Florenz Ames. Iola: Carole Ann Campbell.

1x5 - The Mystery of Cabin Island / The Hidden Harbor Mystery

October 4, 1969

1x6 - The Secret of the Caves / A Figure In Hiding

October 11, 1969

1x7 - The Ghost at Skeleton Rock / The Mystery of the Chinese Junk

October 18, 1969

1x8 - The Shore Road Mystery / The Sign of the Crooked Arrow

October 25, 1969

1x9 - What Happened at Midnight / The Clue in the Embers

November 1, 1969

1x10 - The Clue of the Screeching Owl / The Yellow Feather Mystery

November 8, 1969

1x11 - The House on the Cliff / Mystery of the Spiral Bridge

November 15, 1969

1x12 - The Mystery at Devil's Paw / The Haunted Fort

November 22, 1969

1x13 - The Sinister Signpost / The Melted Coins

November 29, 1969

1x14 - The Mark on the Door / The Flickering Torch Mystery

December 6, 1969

1x15 - The Secret of Wildcat Swamp / The Clue of the Broken Blade

December 13, 1969

1x16 - The Hooded Hawk Mystery / The Short Wave Mystery

December 20, 1969

1x17 - The Phantom Freighter / The Secret of Pirates Hill

December 27, 1969