Solution: The First Lodger at the Grand Hotel

The clues

• 
  BrunoThe cook who tastes everything.

  He was in the Corridor.

• 
  Irene · VictimThe architect restoring the east wing.

  The victim. She was alone with the killer. She was beside a chair.

• 
  JonasThe shy librarian.

  He was in the second column from the left.

• 
  FelixThe student who never sleeps.

  He was in the third row. He was alone in the room.

• 
  NoraThe village doctor.

  She was on a sofa.

• 
  GretaThe gardener who talks to her roses.

  She was beside a sofa. She was alone in the room.

Step by step

The order our solver finds. Each step uses only the clues and what the steps before it proved, and its heading links to the technique.

1. Pinned suspects Felix can only be in the third row, so nobody else can be there.
2. Pinned suspects Jonas can only be in the second column from the left, so nobody else can be there.
3. The only one who fits Only Jonas can still reach the second row, so he must be there. Placed: Jonas: row 2, column 2 (Lounge).
4. Room counting The victim, Irene, cannot be in the highlighted cells: her room there could not hold exactly one other person. The cells meant: row 5, column 3.
5. Room counting Felix cannot be in the highlighted cells: he would not be alone there. The cells meant: row 3, column 1; row 3, column 3; row 3, column 4.
6. Room counting Felix was alone in the Bar. Nobody else can be in that room.
7. The only one who fits Only Felix can still reach the right column, so he must be there. Placed: Felix: row 3, column 6 (Bar).
8. Shared rows and columns Bruno and Irene can only be in the fourth row and the fifth row between them, so nobody else can be in those rows.
9. Pinned suspects Greta can only be in the third column from the left, so nobody else can be there. Placed: Nora: row 1, column 4 (Reading Room); Greta: row 6, column 3 (Cloakroom).
10. Pinned suspects Irene can only be in the fifth row, so nobody else can be there.
11. Room counting Greta was alone in the Cloakroom. Nobody else can be in that room. Placed: Irene: row 5, column 5 (Corridor); Bruno: row 4, column 1 (Corridor).