The Casebooks

Solve the Mystery. Sharpen Your Mind.

Each Ivy X. Locke casebook presents one complete investigation, filled with suspects, evidence, clues, and a truth waiting to be uncovered. No apps or game pieces—just careful reading, sharp logic, and a pencil.

Standalone Lore
Pure Logic
Interactive Verification

Strengthen Your Observation

Build Your Deductive Thinking

Challenge Your Focus

Notice the details others miss, compare the evidence, and learn to spot patterns that matter.

Test each possibility, eliminate what cannot be true, and follow the logic to the only answer that fits.

Stay with the case from clue to clue, keep track of your reasoning, and enjoy the satisfaction of solving it yourself.

Choose Your Investigation

Each casebook presents a different mystery, a new set of evidence, and one truth waiting to be uncovered.

View the Case
book cover of the Missing Guest Listy Logic Puzzlebook cover of the Missing Guest Listy Logic Puzzle
Book cover for The Midnight Gondola, a Venetian murder-mystery logic puzzle by Ivy X. Locke.Book cover for The Midnight Gondola, a Venetian murder-mystery logic puzzle by Ivy X. Locke.

Available Cases here...

A dark Venetian canal at night, a single black gondola floating near a decaying gothic palace entrance, low-key candlelight reflecting on water
A dark Venetian canal at night, a single black gondola floating near a decaying gothic palace entrance, low-key candlelight reflecting on water
Close-up of a vintage brass astrolabe and star charts on a dark wood table, illuminated by a single warm candle, deep shadows
Close-up of a vintage brass astrolabe and star charts on a dark wood table, illuminated by a single warm candle, deep shadows

FEATURED INVESTIGATION

The Midnight Gondola

A collector is found dead after a midnight gondola crossing, and the killer is hidden among 11,016 passenger records. Follow twenty essential clues through masks, seals, tickets and registry positions to identify the passenger behind the mask.

Releasing Soon

The Observatory Murders

An isolated mountaintop observatory becomes a frozen tomb. Decipher stellar charts, mechanical brass orrery gears, and cold-temperature alibis to catch a killer among scientists.

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