Frontier Logic

Daily case

Frontier Logic Daily No. 89 December 2, 2026 Rookie

The Sinkhole Draw Inquiry: a free Western logic-grid puzzle

They're still arguing about what happened near Sinkhole Draw. The facts, such as they are, are written here. There's an answer in here. Find it.

This free Rookie logic-grid puzzle has 4 suspects, 4 locations, and 4 pieces of evidence. New to logic grids? Start with the pencil-solving guide.

How to mark the grid

●
These two belong together.
✕
These two are ruled out.
blank
Still undecided.
How to play

Click, tap or press Enter on a cell to cycle it: blank, then ● for a confirmed pairing, then ✕ for one you have ruled out. Nothing fills itself in — the deductions are yours to make. Use the arrow keys to move around the grid.

Fill obvious Xs does the bookkeeping only: for each ● you have marked, it crosses off the rest of that pairing's own row and column. It never adds a ●, never reads a clue, and never changes a mark you made.

On a narrow screen the grid scrolls sideways.

Every case has exactly one solution, and it is always reachable by deduction alone. Nothing here guesses for you, and Check will not tell you which mark is wrong.

Clues and evidence

  1. Ottie Gaunt was at Malachite Butte — that much is settled.
  2. Machinist Dora Lathe swore never to have set foot in Alkali Flat, and the ledger agrees.
  3. Ottie Gaunt never laid hands on the worn fuse pouch.
  4. Machinist Dora Lathe wasn't carrying the knotted whipcord.
  5. The deputy struck the worn fuse pouch off Machinist Dora Lathe's account.
  6. The knotted whipcord never belonged to Ottie Gaunt.
  7. You can rule out the filed scale weight for Machinist Dora Lathe.
  8. The deputy struck Signal Peak off Judge Amos Pell's account.
  9. Machinist Dora Lathe kept well clear of Signal Peak.
  10. The worn fuse pouch never belonged to Judge Amos Pell.

The grid

On a narrow screen the grid scrolls sideways.

Your marks, completions and streak are saved in this browser only. There is no account, and clearing your browser data clears that local progress. If you accept analytics, the site sends anonymous puzzle-usage events; it never sends your grid marks, clues or solution.

If you want a hundred more

Five volumes, printed and portable

Each Frontier Logic volume collects 100 western mystery logic-grid puzzles, every one with exactly one solution and a complete answer key. Every volume stands alone, in standard and large print.

Opens Amazon, who sell the books and set the final price.