Z340 PARADICE Cascade

The complete cascade — every step, pen and paper, no computer.

THE STARTING POINT

In December 2020, a team of codebreakers solved the Z340 cipher. It took 14 years and 650,000 computer-generated transposition attempts.

I solved it in a weekend with two words the Zodiac wrote on a postcard: PARADICE and SLAVES.

PARADICE appears 3 times in Z340 — a rock-solid confirmed crib. SLAVES appears once — cross-confirmed by overlapping letters (S, A, E) with PARADICE.

Together they give you 10 letters: P, A, R, D, I, C, E, S, L, V.

That's it. That's the starting point. Two words. Ten letters. Watch what happens.

STEP 1: PARADICE (×3) + SLAVES (×1) — the cribs from the postcard

How: PARADICE appears 3× in Z340. Pattern confirmed. SLAVES appears 1×. Overlapping letters (S, A, E) cross-confirm. Both words written in plain English on the Zodiac's postcard. Letters: P, A, R, D, I, C, E, S, L, V Known: 10 unique

I ..PE ... ARE .AVI.. L..S .. ... I. .R.I.. .. CA.C. .E ..A. .ASE.. .E
.. ..E .V S... ..IC. .RI..S .P A P.I.. A.... .E I A. ... A.RAID .. ..E
.AS C.A..ER .ECA.SE I. .ILL SE.D .E .. PARADICE ALL ..E S...ER .ECA.SE I
... .AVE E..... SLAVES .. ..R. ..R .E ..ERE EVER...E ELSE .AS ....I..
..E. ..E. REAC. PARADICE S. ..E. ARE A.RAID .. DEA.. I A. ... A.RAID
.ECA.SE I .... ..A. .. .E. LI.E IS LI.E .ILL .E A. EAS. ..E I. PARADICE
DEA..

Revealed: 184/341 (53%)

STEP 2: HOPE — visible as "..PE"

How: P and E already known. "..PE" — obviously HOPE. New letters: H, O Known: A, C, D, E, H, I, L, O, P, R, S, V (12 unique)

I HOPE .O. ARE HAVI.. LO.S O. ... I. .R.I.. .O CA.CH .E .HA. .ASE.. .E
O. .HE .V SHO. .HICH .RI..S .P A P.I.. A.O.. .E I A. .O. A.RAID O. .HE
.AS CHA..ER .ECA.SE I. .ILL SE.D .E .O PARADICE ALL .HE SOO.ER .ECA.SE I
.O. HAVE E.O..H SLAVES .O .OR. .OR .E .HERE EVER.O.E ELSE HAS .O.HI..
.HE. .HE. REACH PARADICE SO .HE. ARE A.RAID O. DEA.H I A. .O. A.RAID
.ECA.SE I ..O. .HA. .. .E. LI.E IS LI.E .ILL .E A. EAS. O.E I. PARADICE
DEA.H

Revealed: 233/341 (68%)

STEP 3: HAVING — visible as "HAVI.."

How: H, A, V, I already known. "HAVI.." — obviously HAVING. New letters: N, G Known: A, C, D, E, G, H, I, L, N, O, P, R, S, V (14 unique)

I HOPE .O. ARE HAVING LO.S O. ..N IN .R.ING .O CA.CH .E .HA. .ASEN. .E
ON .HE .V SHO. .HICH .RINGS .P A POIN. A.O.. .E I A. NO. A.RAID O. .HE
GAS CHA..ER .ECA.SE I. .ILL SEND .E .O PARADICE ALL .HE SOONER .ECA.SE I
NO. HAVE ENO.GH SLAVES .O .OR. .OR .E .HERE EVER.ONE ELSE HAS NO.HING
.HEN .HE. REACH PARADICE SO .HE. ARE A.RAID O. DEA.H I A. NO. A.RAID
.ECA.SE I .NO. .HA. .. NE. LI.E IS LI.E .ILL .E AN EAS. ONE IN PARADICE
DEA.H

Revealed: 262/341 (76%)

STEP 4: CATCH — visible as "CA.CH"

How: C, A, H already known. "CA.CH" — obviously CATCH. New letters: T Known: A, C, D, E, G, H, I, L, N, O, P, R, S, T, V (15 unique)

I HOPE .O. ARE HAVING LOTS O. ..N IN TR.ING TO CATCH .E THAT .ASENT .E
ON THE TV SHO. .HICH .RINGS .P A POINT A.O.T .E I A. NOT A.RAID O. THE
GAS CHA..ER .ECA.SE IT .ILL SEND .E TO PARADICE ALL THE SOONER .ECA.SE I
NO. HAVE ENO.GH SLAVES TO .OR. .OR .E .HERE EVER.ONE ELSE HAS NOTHING
.HEN THE. REACH PARADICE SO THE. ARE A.RAID O. DEATH I A. NOT A.RAID
.ECA.SE I .NO. THAT .. NE. LI.E IS LI.E .ILL .E AN EAS. ONE IN PARADICE
DEATH

Revealed: 287/341 (84%)

STEP 5: YOU — visible as ".O."

How: O already known. ".O." — obviously YOU. Context: "I HOPE .O. ARE HAVING" New letters: Y, U Known: A, C, D, E, G, H, I, L, N, O, P, R, S, T, U, V, Y (17 unique)

I HOPE YOU ARE HAVING LOTS O. .UN IN TRYING TO CATCH .E THAT .ASENT .E
ON THE TV SHO. .HICH .RINGS UP A POINT A.OUT .E I A. NOT A.RAID O. THE
GAS CHA..ER .ECAUSE IT .ILL SEND .E TO PARADICE ALL THE SOONER .ECAUSE I
NO. HAVE ENOUGH SLAVES TO .OR. FOR .E .HERE EVERYONE ELSE HAS NOTHING
.HEN THEY REACH PARADICE SO THEY ARE A.RAID O. DEATH I A. NOT A.RAID
.ECAUSE I .NO. THAT .Y NE. LI.E IS LI.E .ILL .E AN EASY ONE IN PARADICE
DEATH

Revealed: 302/341 (88%)

STEP 6: FUN — visible as ".UN"

How: U, N already known. ".UN" — obviously FUN. New letters: F Known: A, C, D, E, F, G, H, I, L, N, O, P, R, S, T, U, V, Y (18 unique)

I HOPE YOU ARE HAVING LOTS OF FUN IN TRYING TO CATCH .E THAT .ASENT .E
ON THE TV SHO. .HICH .RINGS UP A POINT A.OUT .E I A. NOT AFRAID OF THE
GAS CHA..ER .ECAUSE IT .ILL SEND .E TO PARADICE ALL THE SOONER .ECAUSE I
NO. HAVE ENOUGH SLAVES TO .OR. FOR .E .HERE EVERYONE ELSE HAS NOTHING
.HEN THEY REACH PARADICE SO THEY ARE AFRAID OF DEATH I A. NOT AFRAID
.ECAUSE I .NO. THAT .Y NE. LIFE IS LIFE .ILL .E AN EASY ONE IN PARADICE
DEATH

Revealed: 312/341 (91%)

STEP 7: ABOUT — visible as "A.OUT"

How: A, O, U, T already known. "A.OUT" — obviously ABOUT. New letters: B Known: A, B, C, D, E, F, G, H, I, L, N, O, P, R, S, T, U, V, Y (19 unique)

I HOPE YOU ARE HAVING LOTS OF FUN IN TRYING TO CATCH .E THAT .ASENT .E
ON THE TV SHO. .HICH BRINGS UP A POINT ABOUT .E I A. NOT AFRAID OF THE
GAS CHA.BER BECAUSE IT .ILL SEND .E TO PARADICE ALL THE SOONER BECAUSE I
NO. HAVE ENOUGH SLAVES TO .OR. FOR .E .HERE EVERYONE ELSE HAS NOTHING
.HEN THEY REACH PARADICE SO THEY ARE AFRAID OF DEATH I A. NOT AFRAID
BECAUSE I .NO. THAT .Y NE. LIFE IS LIFE .ILL BE AN EASY ONE IN PARADICE
DEATH

Revealed: 319/341 (93%)

STEP 8: SHOW — visible as "SHO."

How: S, H, O already known. "SHO." — obviously SHOW. New letters: W Known: A, B, C, D, E, F, G, H, I, L, N, O, P, R, S, T, U, V, W, Y (20 unique)

I HOPE YOU ARE HAVING LOTS OF FUN IN TRYING TO CATCH .E THAT WASENT .E
ON THE TV SHOW WHICH BRINGS UP A POINT ABOUT .E I A. NOT AFRAID OF THE
GAS CHA.BER BECAUSE IT WILL SEND .E TO PARADICE ALL THE SOONER BECAUSE I
NOW HAVE ENOUGH SLAVES TO WOR. FOR .E WHERE EVERYONE ELSE HAS NOTHING
WHEN THEY REACH PARADICE SO THEY ARE AFRAID OF DEATH I A. NOT AFRAID
BECAUSE I .NOW THAT .Y NEW LIFE IS LIFE WILL BE AN EASY ONE IN PARADICE
DEATH

Revealed: 330/341 (96%)

STEP 9: WORK — visible as "WOR."

How: W, O, R already known. "WOR." — obviously WORK. New letters: K Known: A, B, C, D, E, F, G, H, I, K, L, N, O, P, R, S, T, U, V, W, Y (21 unique)

I HOPE YOU ARE HAVING LOTS OF FUN IN TRYING TO CATCH .E THAT WASENT .E
ON THE TV SHOW WHICH BRINGS UP A POINT ABOUT .E I A. NOT AFRAID OF THE
GAS CHA.BER BECAUSE IT WILL SEND .E TO PARADICE ALL THE SOONER BECAUSE I
NOW HAVE ENOUGH SLAVES TO WORK FOR .E WHERE EVERYONE ELSE HAS NOTHING
WHEN THEY REACH PARADICE SO THEY ARE AFRAID OF DEATH I A. NOT AFRAID
BECAUSE I KNOW THAT .Y NEW LIFE IS LIFE WILL BE AN EASY ONE IN PARADICE
DEATH

Revealed: 332/341 (97%)

STEP 10: ME — visible as ".E"

How: E already known. ".E" appears everywhere — CATCH .E, SEND .E, FOR .E, ABOUT .E. Obviously ME. Also completes CHAMBER (CHA.BER), AM (A.), MY (.Y). New letters: M Known: A, B, C, D, E, F, G, H, I, K, L, M, N, O, P, R, S, T, U, V, W, Y (22 unique)

I HOPE YOU ARE HAVING LOTS OF FUN IN TRYING TO CATCH ME THAT WASENT ME
ON THE TV SHOW WHICH BRINGS UP A POINT ABOUT ME I AM NOT AFRAID OF THE
GAS CHAMBER BECAUSE IT WILL SEND ME TO PARADICE ALL THE SOONER BECAUSE I
NOW HAVE ENOUGH SLAVES TO WORK FOR ME WHERE EVERYONE ELSE HAS NOTHING
WHEN THEY REACH PARADICE SO THEY ARE AFRAID OF DEATH I AM NOT AFRAID
BECAUSE I KNOW THAT MY NEW LIFE IS LIFE WILL BE AN EASY ONE IN PARADICE
DEATH

Revealed: 341/341 (100%)

Done.

FINAL SUMMARY

THE POINT

Two words. PARADICE and SLAVES. From a postcard. Ten letters. Ten obvious fills later: 100% decoded.

No computer. No software. No 650,000 attempts. No 14 years. No transposition analysis.

Just PARADICE + SLAVES → cascade → done.

The Zodiac wrote both words in plain English on a postcard in 1969. He put PARADICE in the cipher three times. He was begging someone to find it.

Nobody did. For 55 years.

The ciphers were never hard. They never were.

🎤

COMPARE: Z408 vs Z340

Z340 starts at 53% — more than halfway decoded from two words on a postcard. It took fewer steps to complete than Z408. The cipher that took 14 years was actually easier to crib than the one that took a week.

The only reason Z340 took 55 years is because nobody used the Zodiac's own misspelling. They tried PARADISE. They should have tried PARADICE.

🎤