Moriarty’s Game: The Professor’s Invitation by HiddenCity

London turns into a mystery game. Moriarty’s Game: The Professor’s Invitation is a phone-led treasure hunt across Marylebone and nearby West End streets, with planned break points along the way. I like the way it turns everyday London corners into story locations you can actually search, not just look at. One catch: you must have a UK, US, or CA mobile phone number ready to play.

What makes it work is the pacing. You solve clue trails on your phone, pause when you need a reset, and keep moving at your own speed instead of marching as one big group. Refreshments are available at the break points, but you cover those costs yourself.

You’ll play in teams of 2 to 6, and if your group is larger you’ll split into multiple teams so everyone has a chance to participate. The run time is about 3 to 4 hours, and it starts in Marylebone before ending in Mayfair.

Key takeaways before you go

• Phone-required clue solving means you’ll navigate using the story’s trail, not a printed route
• Marylebone-to-Mayfair walking gives you West End texture without only sticking to the obvious sights
• Team play (2–6) keeps the game from feeling slow or over-competitive
• Pause anytime so you can go at your own pace and regroup after tougher clues
• Refreshments at break points are built in, but you pay for them
• Private for your group so you’re not mixed into strangers’ teams

Moriarty’s Game in Marylebone: a West End walk you control

This is one of those London activities that flips the usual script. Instead of “see this, then see that,” you get a story prompt and a trail of clues that pulls you along streets where the fun is in the searching. The start point anchors you in Marylebone, and the route keeps shifting toward the West End feel as you solve your way forward.

I especially like that it’s designed for real groups. Whether you’re a couple, a family with kids old enough to follow phone prompts, or a group of friends, teams of 2 to 6 keep decisions local. You’re not waiting for one person to read everything out loud to everyone else, and you’re not stuck with a large blob of people pretending to be in sync.

There’s also a practical benefit: because you can pause the tour, you’re not forced to keep moving when your legs are done or when the group needs a snack and a reset. In a city like London, that flexibility matters more than you think.

How the phone clue trail works (and why it feels different)

The engine of the experience is your phone. You receive clue messages that act like the game’s map, then you use those hints to find the next story location. It’s not a static walking route where the fun is done once you get to the listed spot. Here, the fun is in solving riddles and puzzles that lead you to where you should go next.

The tour is framed as a treasure hunt with a narrative layer. You’re meant to play a role in the story as you uncover secret locations and work through puzzles, which makes the walk feel more like a mission than a sightseeing loop. Even if you’re not a superfan of crime fiction, that structure helps you stay engaged because every turn has a reason.

One more detail that’s helpful: you can pause at any time. That means if you get stuck on a clue, you can regroup without panicking that you’re falling behind. It also makes the whole experience more family-friendly, since younger players can take a breather while the team figures out what the phone is asking.

The 3–4 hour pace: what to expect from start to finish

You’re looking at about 3 to 4 hours total, which is a sweet spot for a London walking activity. Long enough that you’ll cover multiple neighborhoods, but short enough that you can still do a normal dinner plan after.

The start is Marylebone High Street, at 93 Marylebone High St, London W1U 4RD. From there, you follow the clue chain across Marylebone and beyond, then the experience ends in Mayfair. That Marylebone-to-Mayfair arc is useful because it gives you variety: more local, quieter-feeling streets around Marylebone, then the more polished West End vibe as you head toward Mayfair.

A small but real planning tip: because you’ll be stopping for breaks at built-in points, treat the duration as a window. You’re not just walking for 3 hours straight; you’re also thinking, checking the next clue, and taking short stops.

Teams of 2–6: how group size affects the game

This is built for teamwork. You’ll play in teams of 2 to 6 players, and if your group is too large, it gets split into multiple teams. That helps keep everyone involved instead of turning the experience into a spectator sport for part of your party.

For friend groups, this also changes the energy. Teams can effectively compete while still working toward the same general mission. For families, it helps too because kids can be assigned to specific tasks like reading the next prompt or scanning for the next location cue.

One practical consideration: bring enough phone power for your team. Since you need a mobile number to take part, you’ll be leaning on your phone throughout. If your battery tends to run out on a busy day, plan to top up before you start.

Break points and refreshments: plan to eat on your schedule

The tour includes selected break points where you can take a breather. Refreshments are available at these moments, but they’re own expense, so you’re free to choose what fits your budget and dietary needs.

I like this approach. London tours often either rush you through stops or pretend snacks magically appear. Here, the breaks are part of the design, so you’re not waiting for a moment to happen. It also makes pacing more realistic—think water, a quick bite, and then getting back to clues without everyone spiraling into hanger.

If you’re traveling with kids, this is a big plus. A game that supports snack stops is usually easier than one that expects everyone to power through without breaks.

The London streets you get: why this route feels more local

The stated goal is to visit locations in the West End that don’t typically show up in standard guidebook walks. That’s not just marketing fluff. When a game is built around secret locations and puzzle clues, you naturally move through the smaller streets and less obvious corners, because those are the places where a clue can point you somewhere specific.

From the practical perspective, that means you’ll get a more textured view of the West End than the usual “big landmark” approach. You’ll still be in central London, but you’ll spend time in the in-between spaces that make neighborhoods feel lived-in.

I also appreciate that the experience is described as suitable for families and friend groups. Many “mystery” style tours can quietly become too intense or too complicated for mixed-age groups. The game design here is meant to stay friendly while still being engaging.

The start in Marylebone and the end in Mayfair: a useful half-day arc

Location matters because London can feel endless. Starting at 93 Marylebone High St puts you in a straightforward area to find, with public transport nearby. The end point in Mayfair gives you flexibility for your next step, too: it’s a convenient landing zone if you want to continue with shopping, museums, or an early dinner without doubling back.

Also, because the end is in a different neighborhood than the start, it avoids the classic problem of feeling like you’ve traveled a loop and then still need to figure out how to get back where you started. You finish somewhere else and can move on easily.

Value for $40.90: what you’re really paying for

At about $40.90 per person, this isn’t a bargain-basement activity. But you’re also paying for more than walking in a neighborhood. You’re getting:

• a guided story experience through multiple locations
• phone-based puzzle mechanics that control your route
• built-in break points that reduce decision fatigue
• team-based gameplay that keeps everyone participating

In other words, the “value” is in the structure. You pay to turn time in London into a coordinated game with pacing built in, rather than piecing together your own scavenger hunt. If you like interactive activities and you want something that feels different from museum days, this price is easier to justify.

One good budgeting note: you’ll likely spend extra during the break points because refreshments are own expense. Build a little cushion so the game stays fun, not stressful.

HiddenCity’s Moriarty’s Game: best fit for your travel style

This experience fits best if you want:

• a fun, story-driven walk
• an activity that works for groups
• a route that’s more about clues and streets than checklist sightseeing
• the option to pause and adjust pace

It also tends to be a smart pick for people who don’t love rigid group tours. Because you can stop anytime and go at your own pace, you’re not trapped in someone else’s schedule.

If you’re the type who loves planning your own city day with printed maps and solo exploration, this might feel a bit more structured than you prefer. But if you want London to feel like a game without doing the homework yourself, this is the kind of plan that delivers quickly.

Practical notes that can make or break your game

There are a couple of details I’d treat as “check before you leave” items.

First, you need a mobile phone number from the UK, US, or CA to take part. That matters because the game uses phone clue delivery, and that number is required. If you’re traveling with only a non-UK/US/CA number, this could be a dealbreaker—so verify early.

Second, you’ll be playing in teams of 2–6. If you’re traveling solo, it may still work depending on how your party forms, but the core design assumes you’re grouping up. If you’re traveling as a small party and want help coordinating, plan ahead.

Third, service animals are allowed and public transportation is nearby. That’s helpful to know for many visitors, though the tour’s description doesn’t spell out step-by-step accessibility details beyond that.

Finally, the company is described as accommodating when issues come up, and communication has been praised. If you run into trouble, it’s worth reaching out early rather than waiting.

Should you book Moriarty’s Game: The Professor’s Invitation?

Book it if you want an interactive London activity that gets you moving through Marylebone and the West End with a clear purpose. You’ll likely enjoy it most if you like puzzles, team problem-solving, and the idea of pausing when you need to instead of sticking to a strict march.

Skip or rethink it if you don’t want to rely on your phone, or if you’re not able to provide a UK, US, or CA mobile number. The phone requirement is the one constraint that can’t be hand-waved.

If your ideal day includes a half-day game that turns streets into clues—and you’re okay paying a standard London price plus a little for breaks—this is a strong pick.

FAQ

How long is Moriarty’s Game: The Professor’s Invitation?

It runs about 3 to 4 hours.

What does the tour cost?

The price is $40.90 per person.

Where does the experience start?

You start at 93 Marylebone High St, London W1U 4RD, UK.

Where does it end?

The experience ends in Mayfair, London.

Do I need a mobile phone number to take part?

Yes. A UK, US, or CA mobile phone number is required to participate.

What team sizes does the game support?

It’s played in teams of 2 to 6 players, and larger groups are split into multiple teams.

Are refreshments included?

Breaks are built into the experience, but refreshments are own expense.

What if I need to cancel?

You can cancel for free up to 24 hours in advance of the experience’s start time for a full refund. If you cancel less than 24 hours before, the amount paid is not refunded.