Goal: produce a complete, consistent logbook entry for each person.
Tap a note → tap a grid cell → assign a time.
- Anchors first: any note that states a place and a time pins that column.
- Eliminate: use — to rule out impossible person × place cells.
- Assign times: each time (08:00, 09:00, 10:00) can appear only once overall.
- Verify: press Verify alibis once every person has exactly one time placed.
- Forced move finds a mark that must be true across all remaining valid logs.
Common mistake: guessing early. This puzzle is designed to be solved by elimination, not intuition.