The Cross
Sometimes a suspect’s possible tiles form a plus sign: some lie in one row, the rest in one column, and the row and column cross at a single tile. That shape tells you something about the tile where they meet, even if the suspect could never stand on it.
Wherever the suspect ends up, they use either that row or that column. If they are in the row, nobody else can be anywhere in the row — including that meeting point. If they are in the column, nobody else can be anywhere in the column — the meeting point again. Either way, no one else can stand there. And if the suspect could not stand there themselves, nobody can: the tile is dead for the whole board.
When the Shape Appears
The cross comes from object clues more than any other kind. “On a chair” confines a suspect to the chairs, and when the chairs in a room are arranged along one row and down one column — a dining table with seats on two sides, say — the shape is a cross. The same happens with “beside a window” on a corner room, where the windows run along two walls.
It also turns up as a case thins out. A suspect who started with many tiles can be cut down to two short strips that happen to meet, and nothing about the clue text hints at it. It is worth glancing at any suspect with five or six tiles left and asking whether those tiles form a cross.
Why It Is Safe
This one can feel like a trick, so it is worth seeing why it can never be wrong. If someone else stood on the crossing tile, they would occupy both the row and the column. The confined suspect has to be in one of those two lines. Two people in one line is exactly what the first rule forbids. There is no arrangement in which the crossing tile is used by anyone but the suspect — so if the suspect cannot use it either, it stays empty.
A Worked Example
From the case Small Farm, Big Murder — 6×6, Medium, Farm.
| C1 | C2 | C3 | C4 | C5 | C6 | |
|---|---|---|---|---|---|---|
| R1 | Co | M | T | T | ||
| R2 | Co | |||||
| R3 | C | M | W | |||
| R4 | M | W | M | |||
| R5 | C | M | P | R | ||
| R6 | P |
The clues in play:
- Anna — She was beside a chicken
- Bella — She was on a mud puddle and she was alone in a room with a cow
- Carol — She was alone in a room with a pig
- Dalia — She was beside rubble
- Edison — He was beside a tree
This step comes before anyone in the case is placed, so reading it does not give the solution away.
At step 7 of the solve, the reasoning reads:
Bella can only be in row 1 or column 3; so their intersection R1/C3 can hold no one (not a cell for Bella, blocked for everyone else) – removed.
Cases That Need It
30 of the 142 cases in the casebook use this technique at least once. A selection, smallest board first:
- Murder in a Minor Key — 6×6, Medium, House & Home
- Small Farm, Big Murder — 6×6, Medium, Farm
- The Mole — 6×6, Hard, Precinct & Office
- Animal Instincts — 7×7, Medium, Farm
- Death at the Diving Board — 7×7, Medium, Pool & Spa
- Last Rites — 7×7, Hard, Auto shop
- Murder in the OR — 7×7, Hard, Hospital
- Among Old Friends — 8×8, Hard, Campground
- Beware of Bears — 8×8, Hard, Campground
- Mörderisches Obst — 8×8, Hard, Supermarket
- Please Don't Feed the Killer — 8×8, Medium, Zoo
- Steam and Silence — 8×8, Medium, Pool & Spa
Other Techniques
- The Last Tile
- Only One Fits the Line
- Locked Lines
- One Free Tile
- Clues That Tie People Together
- Who Else Was in the Room
- Alone With the Victim
- Beside the Same Object
- Counting the Whole Scene