How to solve a Night Desk case

What a case asks

Each case has four suspects (five on Sundays), four places and four means. Every suspect was in a different place and held a different thing. Exactly one of them did it. Your accusation names three things: who, how (which means) and where. The case file tells you what happened and lists the people, places and means; it never gives you enough to answer on its own.

Ask about places first

Start with everyone's alibi. Each place holds exactly one person, so every "I was in the kitchen" removes a place from three other people at once. Then ask what each person noticed and what they saw the others holding: those answers usually carry the clues about the means. The victim, the item and the motive topics are worth one question each, mostly for color and the occasional surprise.

Every new question counts toward your score. Asking the same person the same thing again is free, so never be shy about rereading. A sharp solve is one accusation, right the first time, within the case's par: the fewest questions that settle it, plus three.

Work the board

The board has two grids: who was where, and who had what. Tap a square once for an X (ruled out) and twice for a check (confirmed). The board never fills itself in. Three rules do most of the work:

• One check per row and per column. When you confirm a square, X the rest of its row and its column.
• The last empty square is a check. If a row or column has every square but one ruled out, the one left is true.
• "Whoever was at X had Y" links the grids. A clue like "whoever stood at the office door carried the ledger" means the person in the office column of the first grid is the person in the ledger column of the second. Once either side is known, the other follows.

Tap a clue card in the notebook and the squares it is about light up, which makes it easy to check you have marked everything a clue says.

A worked example: the harbor clock

A practice case, not one from the season. Someone stopped the harbor clock. Three people were about: Ash, Bell and Cole, one each on the quay, in the office and in the shed. One had a crowbar, one a key and one a rope. The clock case was opened with the key. Five clues came out of the questioning:

1. Bell was in the office.
2. Ash was not on the quay.
3. Whoever was on the quay had the rope.
4. Cole did not have the key.
5. Ash had the crowbar.

Clue 1 puts a check on Bell and the office, and X's the rest of Bell's row and the office column. Clue 2 X's Ash on the quay, which leaves Ash only the shed, and that leaves Cole the quay. Clue 3 links the grids: Cole was on the quay, so Cole had the rope. Clue 4 agrees with that and adds nothing new; that happens, and it is a good check on your marks. Clue 5 gives Ash the crowbar, so Bell had the key. The clock was opened with the key, so it was Bell, with the key, in the office.

Notice that the motive never came into it. In a real case someone will have an excellent reason to stop that clock, and it will usually not be the person who did.

When someone lies

Some cases, and every Sunday cold case, say that one person lies, and that the liar is the guilty party. Everyone else tells the truth. Lay every claim on the board in pencil and look for a collision: two claims that cannot both be true, such as two people who both say they were in the dining room. The liar is one of those two. Assume each in turn is lying, flip their claims, and see whether the honest testimony still fits. One guess breaks something; the other is your liar. Only then flip the liar's words and use them.

Times and stops in order

In a timeline case the places are in order, such as ferry stops or times of night, and clues say "before", "after" or "right after". Pin the ends first: someone who got off before the second stop can only have got off at the first. A "right after" clue is a hinge between two people; once one is placed, the other has one square left.

Documents

Forged document cases put an exhibit on the desk: a letter, a ticket or a receipt. Choose the exhibit beside the suspects and examine each mark on it. A mark can tell you how the forgery was made, or where, and it counts as a question like any other.

Accusing, and Grane's rebuttals

You have three accusations. On the first wrong one, Chief Inspector Grane only tells you it does not hold. From the second, he names the parts that are wrong: who, how or where. Use that well. If he says your who and your where hold, the only thing left to fix is the means, and the board will show you which one. After a third wrong accusation he closes the case and writes it up himself.

Each case's write-up appears once you solve it, or from the night after it opens, so you can always see how it was done.

Ready?

Open tonight's case at The Night Desk, or browse every case of Season 1.