And the Hello, friends. Hello friend, welcome back to foul play.

When an enticing lead appears in one of America's most infamous unsolved serial killer cases.

It's like a siren calling for an adventurous investigative journalist.

Paul Avery was a seasoned reporter for the San Francisco Chronicle.

He had written extensively on the Zodiac case.

On October 27th, 1970, after covering the mysterious and elusive killer across the Bay Area.

The game then changed.

Avery found himself under the watchful gaze of the self-proclaimed Zodiac.

A Halloween postcard bearing Paul Avery's name showed a haunting depiction of a skeletal figure with a pumpkin for a torso.

The cardboard the inscription from your secret pal, accompanied by the words, I feel it in my bones, you ache to know my name,

and so I'll clue you in.

To the left of the skeleton, the word slaves was handwritten horizontally in eerie capital letters.

Vertical letters also in capitals, spell out the word Paradise with a letter C instead of an

S. The Zodiac's trademark misspelling of the word was in keeping with his earlier communications.

Within each corner, the Zodiac had written,

By Fire, by Knife, by gun, and by rope.

On the reverse of the card was another skeleton.

This one is jovial and dancing.

Shapes that looked like eyes were dotted all around.

The word booue jumped out in bold, white lettering.

A number four followed by the word teen, written all around the skull of the skeleton

was equally large in bold lettering.

...