Baskerville Hall · early 20th century

Sherlock Holmes & the Return to Baskerville Hall

Holmes is back at Baskerville Hall. The house is full of clues, ciphers and statements that don't quite line up.

Players: Solo or small teams
Solve time: 60–90 min experienced · up to 3 hours new
Setting: Baskerville Hall · early 20th century
Ages: 14+

£12 VAT included

£1.90 UK shipping, free over £75
Hand-packed in Grimsby
14-day returns

The box

Holmes is back at Baskerville Hall, and what was meant to be a quiet weekend has turned into a tangle of clues, ciphers and witness statements that don't quite line up. The puzzles work the way the Great Detective taught — observation first, deduction second, and never trust a footprint that's too neat.

Every card is a small knot to untie, and they all loop back into one final answer. Hand them around the table or settle in by the fire alone with the dog at your feet. About an hour and a half for seasoned puzzlers; longer if you want to savour it.

Sherlock Holmes & the Return to Baskerville Hall puzzle mystery box cover

Inside the box

What's in the box

Every box is hand-packed in Grimsby. Here's what you'll find when you lift the lid.

A stack of standalone puzzle cards

Each one a clue, a cipher or a contradiction in someone's account.
Cross-referencing materials

The cards don't stand alone — answers connect across the deck.
A locked solution

Unwrap it only when you're sure you've cornered your suspect.

A fan of puzzle cards — a Times cutting, a mirror-written note and a handwritten letter — beside the herringbone Sherlock Holmes & the Return to Baskerville Hall box

Before you buy

Common questions

I'm new to Cosykiller — where should I start?

Start with An Inheritance of Murder. It's our gentlest case, built for puzzle-minded beginners — Braille, letter-to-symbol substitutions and one-time cipher pads. The Secret of Site Q is the step up: a longer, cross-referencing investigation that's challenging but solvable. Shadows in the Gallery is our most advanced case, layering Playfair, knock code and Caesar ciphers across a post-war art theft — do it once you've worked one of the others.

How old do you need to be to play?

Cosykiller is written mainly for adults, but families can participate together. Every case is rated 14+ for themes of murder, and Shadows in the Gallery touches on wartime violence and post-war trauma, so we'd steer younger players towards An Inheritance of Murder first.

What's inside a Cosykiller box?

It varies by case, but every box contains a cover letter from Fairhall & Brett Inheritance Recovery — the fictional investigators who brief you on the case — followed by the documents like photographs, ciphers, maps, letters, military archives, telegrams, postcards, and other personal effects collected during the investigation. Some cases include dried botanicals, spices, theatre programmes and small physical objects. Each case is a complete story, with the final solution provided at the end. Nothing to download or sign into.

How long does it take to solve a case?

2-4 hours for our single box solves, and between 6-11 hours for some of our longer games. Length of time also depends on the number of players, and how much you like to re-read and how quick you are at spotting and solving ciphers. Most people spread a case over two or three evenings. You can pause whenever you like — put the lid back on, come back next weekend. Nothing expires.

Can I play solo, or do I need a group?

Both work well. Every case is designed to be solvable on your own — no mechanic depends on a second reader. That said, two to four players is where a case shines, because half the fun is arguing civilly about motive over a drink.

I'm stuck on a code — what do I do?

If you become totally stuck on a code, check out the <a href="https://fairhallandbrett.co.uk/" target="_blank" rel="noopener noreferrer">inheritance hunter's website</a> or join the online community where other detectives swap ideas (link included with your order). If you need one on one help then email <a href="mailto:supersleuth@cosykiller.com">supersleuth@cosykiller.com</a> with your case number and the document you're stuck on and we'll help without spoiling things for you.

All questions

Ready?