Detective’s Notebook

Free sampler

Five Free Hidden Number Puzzles: How the Sampler Works

The five-puzzle sampler is the simplest way to discover the new format. The cases get harder as you go: one Gentle, two Standard and two Fiendish, each with clues that narrow the register to one number.

The Hidden Number Files puzzle book cover by Steve Lewis

What you get

There are five separate puzzles: one Gentle, two Standard and two Fiendish. Tap numbers to cross them out as a clue rules them out, and tap clues to record which ones you have checked. When one number survives, enter it and use Check answer. You can revisit a puzzle or move to the next from the puzzle chooser.

  • Five puzzles across three levels.
  • One verified solution per puzzle.
  • No payment required.

Why the sampler asks for email

Enter an email address to open the sampler. You can choose separately whether to receive marketing updates; leaving that box unchecked does not prevent play. Your marks and answers save automatically in this browser, rather than in an account linked to your email. Use Download progress backup if you want to keep a separate copy; Restore backup lets you continue on another device after opening the sampler there.

Where to go next

If you want to learn a clue type before playing, begin with the clue glossary. For more puzzles, compare the printable and tablet editions on the collection page.