Logic Masters Deutschland e.V.

"The Babel fish is small, yellow, leech-like, and probably the oddest thing in the Universe. It feeds on brainwave energy. It then excretes into the mind of its carrier a telepathic matrix. The practical upshot of all this is that if you stick a Babel fish in your ear you can instantly understand anything said to you in any form of language."

Rules

• Sudoku: Fill the grid with digits 1-9 so that no digit repeats in any row, column or 3×3 box.
• Dynamic Fog: The grid is covered with fog; entering correct digits may clear fog elsewhere, and no guessing is required. Any visible line segments and partial markings continue and connect beneath the fog. Unless revealed, no extra clues should be assumed to exist under the fog.

• Babel fish (Rotational 10‑Complement Symmetry): The puzzle has 180° rotational symmetry about the central Babel fish. For every cell, the digit in that cell and the digit in its rotated counterpart sum to 10. The fish is only otherwise useful if you stick it in your ear.
• Magic Square: The 3×3 box marked by the sparkly square is a magic square (all rows, columns, and diagonals sum to the same value)
• Unknown Killer cages: Digits in the same sized cages sum to the same value to be determined by the solver.

All following variant clues use their standard meanings; full descriptions are provided below.

• Black Dots: A black dot connects two digits where one is exactly double the other.
• Multiple Lines: Every pair of adjacent digits on a white line must have one digit divide evenly into the other.
• V sums: A V connects two digits that sum to 5.
• Zipper Lines: Along a purple line, pairs of digits equidistant from the dot marking the centre sum to the same value.
• Index Lines: Along a cyan line beginning at the square tip, the position of each digit determines another digit’s location. If a digit X appears in the Y‑th position along the line, then a Y must appear in the X‑th position along the same line.
• Entropic Lines: Along a peach line, any three adjacent digits must include one low digit {1,2,3}, one medium digit {4,5,6}, and one high digit {7,8,9}.
• Don’t Panic!: No guessing is required - you are one hoopy frood.

Cheers heaps to Kyunitar, Nico and FIT7Y for their early testing and feedback.

▶️ Walkthrough video coming soon

Other Puzzles

If you enjoyed this, feel free to check out some of my other puzzles:

• Mostly Harmless: Primary Phase
  • Fit the First - Mostly Harmless
  • Fit the Second - Mostly Harmless: Know where your towel is
  • Fit the Third - Mostly Harmless: Zaphod Beeblebrox
  • Fit the Forth - Mostly Harmless: Hyperspace Bypass
  • Fit the Fifth - Mostly Harmless: Beware of the Leopard
  • Fit the Sixth - Mostly Harmless: Heart of Gold
• Mostly Harmless: Secondary Phase
  • Fit the Seventh - Mostly Harmless: Babel Fish <-- You are here
  • Fit the Eighth - releasing 2026-09-11
  • Fit the Ninth - releasing 2026-09-18
  • Fit the Tenth - releasing 2026-09-25
  • Fit the Eleventh - releasing 2026-10-02
  • Fit the Twelfth - releasing 2026-10-09
• Even more at AaronH.net/puzzles