Roboku Español

Puzzles › Case 29

Case 29: who took the Trident of Neptune?

Difficulty: ★★★★☆ · Board 9×9 · 7 suspects

During last night's private gala at the aquarium, a guest must have gotten a little too close to the Trident of Neptune, on display in the Laboratory, because it was gone by morning. The guest list is short; so is the room for error. Help the police unmask the thief.

The board

ABCDEFGHI123456789TableScreenPlantSeatShelfShelfSeatPlant123456789101112

Suspects and clues

Remember the rules: no two suspects (nor the item) ever share a row or a column, each character is in a different room, and the thief is the only one sharing a room with the stolen item. Unsure? Read how to play and the clue types.

Solution

Try it yourself first: pen and paper are enough. When you want to check, open the reasoned solution.

Show the step-by-step solution
  1. Matthew's clue: He's next to a seat. 4 cells remain possible: E6, B7, A8 and B9.
  2. Zara's clue: She's 3 rows away from the Café. 4 cells remain possible: F5, D6, E6 and G6.
  3. Amara's clue: She's 5 columns away from the Laboratory. 2 cells remain possible: C3 and C4.
  4. Lucy's clue: She's not next to any wall. 3 cells remain possible: E2, G2 and F4.
  5. Hugo's clue: He's on the Terrace. 8 cells remain possible.
  6. Gustavo's clue: He's 5 columns away from the Restrooms. It leaves a single cell: D8.
  7. Boris's clue: He's not next to any wall, and he's in row 2. 2 cells remain possible: E2 and G2.
  8. The stolen item's clue: It's right next to the Children's Room. 11 cells remain possible.
  9. Gustavo can only be on D8. No one else can be in row 8 or column D, and no other character can be in the Office.
  10. Every cell still open to Amara is in column C, so no one else can be in that column.
  11. Every cell still open to Boris is in row 2, so no one else can be in that row.
  12. E2 and G2 have already been ruled out, so Lucy can only be on F4. No one else can be in row 4 or column F, and no other character can be in the Main Aquarium.
  13. C4 has already been ruled out, so Amara can only be on C3. No one else can be in row 3 or column C, and no other character can be in the Lobby.
  14. Every cell still open to Zara is in row 6, so no one else can be in that row.
  15. Every cell still open to Matthew is in column B, so no one else can be in that column.
  16. B1, C1, D1, A2, B2, C2 and A3 have already been ruled out, so Hugo can only be on A1.
  17. The item must share its room with one character: the thief. No character can be in the Children's Room any more, so the Trident of Neptune isn't there either.
  18. Zara and Boris can only be in columns E and G. Each takes a different column, so those columns are theirs and no one else can use them.
  19. Every other cell the clue allowed has already been ruled out, so the Trident of Neptune can only be on H7. No one else can be in row 7 or column H.
  20. E6, B7 and A8 have already been ruled out, so Matthew can only be on B9.
  21. The Trident of Neptune can only be in the Restrooms, and Zara is the only character who can still get in there. Since the thief shares a room with the item, Zara must be in the Restrooms.
  22. F5, D6 and E6 have already been ruled out, so Zara can only be on G6. No one else can be in row 6 or column G, and no other character can be in the Restrooms.
  23. G2 has already been ruled out, so Boris can only be on E2.

Conclusion: Zara is the only person sharing the Restrooms with the Trident of Neptune, which is on H7. She is the thief.

ABCDEFGHI123456789TableScreenPlantSeatShelfShelfSeatPlant123456789101112MZALHGBT

Enjoyed it?

The app has hundreds of cases like this one, a new challenge every day and hints when you get stuck. It's free in your browser, on iPhone and on Android.

Play for freeApp StoreGoogle Play