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

A phone-led mystery across London. I like the way this game pulls you around Marylebone and the West End to chase a trail of clues on your phone, making the streets feel personal instead of random. I also like that it’s built for real breaks during the 3–4 hour experience. One thing to plan for: you need a UK, US, or CA mobile phone number to take part.

You can go at your own pace and pause the experience whenever you want, which matters in London with kids, groups with different speeds, or friends who need photo time. It runs in teams of 2–6, and bigger groups can split, so you’re not stuck waiting while one person solves everything.

Key things that make this HiddenCity game worth your time

• A phone-driven clue hunt: you follow instructions and solve riddles using your phone, not a paper map.
• Marylebone to Mayfair, with real street time: you’ll walk neighborhoods instead of sitting in a van.
• Team play (2–6 players): roles feel natural, and larger parties can compete in separate teams.
• Break points built in: you get set moments to grab food and drinks (paid by you).
• West End locations beyond the usual list: the route is designed to include small streets and less expected stops.
• You control the pace: pause anytime without feeling like you’re falling behind.

A phone-led mystery game that turns London streets into a story

Moriarty’s Game: The Professor’s Invitation is a story-style treasure hunt with a simple promise: you’ll follow clues, solve puzzles, and uncover secret-ish spots as you move through London’s West End. The format is what makes it feel different. Instead of a fixed “look here, then here” route, you’re reacting to what the game sends you and what you find in the next stretch of street.

That phone element is also the big practical win. It helps you keep momentum. You’re not trying to decode directions while other people lag behind. You’re also not standing still listening to a long explanation. When the clue drops, you go, and when you need a breather, you take one. The experience is designed for teams of 2–6, so the thinking and the walking both feel shared.

One more reason I like this setup: it fits mixed groups. The tour is pitched for families and friend groups, and it’s designed so you can play at your own pace and pause anytime. That’s useful if you’re with kids, grandparents, or anyone who gets restless when they have to keep moving on someone else’s schedule.

Price and value: what $40.90 buys you in 3–4 hours

At $40.90 per person for roughly 3 to 4 hours, this sits in the “activity you’ll actually do” category. You’re paying for a guided game structure plus access to the hunt experience, not for a generic walking tour where you mostly follow along.

Here’s how I’d judge value with this one:

• Duration vs. cost: 3–4 hours is enough time to feel like you really left the starting point and explored, not just sampled a corner of London.
• You control pacing: pausing without losing the plot reduces stress for groups, which is often what makes or breaks paid activities.
• Team-based fun: you’re not paying for an experience that depends on one person being the puzzle solver. The game works best when 2–6 players can participate.

And there’s a small confidence signal in the reviews: it’s rated 4.8 from 445 reviews, with 95% recommendation. That doesn’t make it automatically perfect, but it does suggest the experience mostly lands as intended—fun, solvable, and well run.

Starting at Marylebone High St and ending in Mayfair

The game starts at Marylebone High St (93 Marylebone High St, London W1U 4RD). From there, your route takes you across Marylebone and then onward toward Mayfair, where the experience ends.

Why this matters for your planning: Marylebone and Mayfair are close enough that the walking feels doable, but far enough that you’re likely to feel like you’re changing neighborhoods during the hunt. In a city as dense as London, that’s a real advantage. You avoid the dead time of long transfers, and you get a better sense of how different blocks and streets feel from one another.

Also, the experience is scheduled for Monday through Saturday, with opening hours listed from 10:30 AM to 6:30 PM (based on the provided date range). So you’ve got flexibility for a mid-morning start through afternoon timing.

One practical note: the end point is Mayfair, not a return to the exact start. If you’ve got plans right after, check the location and make sure you can get to it easily by public transportation.

How the clue trail works on your phone (and what you must have ready)

The core of Moriarty’s Game is the trail of clues sent to your phone. You solve riddles and puzzles as you move from spot to spot, with your “play as your story unfolds” role. It’s essentially a guided mystery you can control in real time.

To take part, you’ll need a UK, US, or CA mobile phone number. That’s not a nice-to-have; it’s required. Before you arrive, double-check that the phone number you’ll use is correct and accessible during the game. If you’re traveling as a group, decide in advance who will hold the phone and whether you’ll all have a chance to take turns with it.

This format also explains why the game can work for different skill levels. The clues are structured enough to keep you moving, but the puzzles are light enough that many groups find it fun rather than frustrating. One review specifically mentioned the game not being too challenging, and that lines up with how puzzle-hunt activities usually work best: enough brainwork to keep it engaging, not so much that you’re stuck.

Team sizes, splitting groups, and friendly head-to-head play

You play in teams of 2 to 6 players. If you show up with a larger group, you can split into multiple teams and play head to head. This is a smart design choice for London groups, because it prevents the common problem of one team being too big for a phone game. It also keeps everyone involved.

Here’s what that means for how you’ll experience it:

• You’ll have people actively scanning, reading clues, and solving.
• You can divide tasks naturally (one person reads, others look around).
• The game’s competitive aspect can add energy without turning it into a stressful contest.

If you’re traveling with friends who like games, this is a great setup. If you’re traveling with family, it’s also workable because the team structure reduces the burden on one person to manage everything.

Break points for snacks: how to handle the food moment without losing time

The experience includes built-in break points where you can stop for food and drinks. The catch is simple: refreshments are your expense.

What I like about built-in breaks in a city hunt is that they reduce decision fatigue. You don’t have to guess when the best time to stop is. You just take the break when the game allows it, then get moving again.

If you’re the type who wants a full meal, plan for it during one of those breaks rather than trying to time dinner perfectly around the final minutes. On the other hand, if you’re just after a quick snack and a water top-up, those built-in moments are ideal.

Because you can pause the tour at any time, you also have some flexibility if your group needs extra time at a break point. Still, the best way to keep the experience fun is to use the provided breaks as your rhythm, not as an open-ended delay.

West End streets you might not find on your own

One of the strongest reasons to book is the route quality: you’ll visit locations in the West End not found in guide books. That’s the practical benefit of a well-designed clue trail. The game gives you permission to wander smaller streets and less obvious corners without feeling like you’re taking a wrong turn.

A review described the experience as taking them through a couple neighborhoods and into cool places, with enjoyment coming from small streets and out-of-the-way areas along the route. That matches what these games usually do best: they turn random walking into a reason to look around.

In London, where “I just want to see pretty streets” can quickly turn into “I’m lost,” a game like this gives structure. You get the feeling of exploration, but with guardrails.

And since the experience is private to your group, you don’t have to worry about blending into a huge crowd. It stays focused on your team.

Vendor communication and getting help when plans change

No matter how perfect an activity sounds, life happens. One review highlighted great communications with the vendor and described accommodation when someone couldn’t attend and needed help with timing later. That’s the sort of real-world detail that matters to me, because it suggests the operator is responsive when something goes off plan.

HiddenCity runs the experience, and based on that kind of feedback, you can treat this as a planned activity rather than a gamble. If you have a tight schedule, it helps to have confidence that the provider will respond and work with you.

Who should book Moriarty’s Game (and who might want to skip it)

This is a strong fit if you want:

• A London activity that feels interactive, not just a lecture-style walk.
• A mystery theme that works for families and friend groups.
• A route that includes Marylebone and Mayfair without requiring you to design a self-guided scavenger hunt.
• A pace you can control with pause anytime freedom.

You might want to think twice if:

• You do not want to use your phone during an activity, since the game relies on clues sent to your phone.
• Your group doesn’t have access to a required mobile number format (UK, US, or CA).
• You need a strict start-to-finish schedule down to the minute, since this is designed for team decision-making and optional pausing.

Should you book this HiddenCity mystery game in London?

If you’re spending a few days in London and you want one activity that’s fun, structured, and different from the usual big-ticket attractions, Moriarty’s Game is a solid pick. The price for a 3–4 hour street-based puzzle hunt is reasonable, especially because teams can split and you get breaks built in. The fact that it’s rated 4.8 and recommended by 95% of people is another good sign.

My biggest deciding factor would be your comfort with phone-based clue solving and your ability to use a UK, US, or CA mobile number. If that’s fine, you’ll likely enjoy the walk through Marylebone and Mayfair and the chance to see West End corners that don’t make the typical checklist.

FAQ

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

It runs about 3 to 4 hours.

Where do you start and where does the game end?

You start at 93 Marylebone High St, London W1U 4RD. The experience ends in Mayfair, London.

How does the game work during the tour?

You’ll travel around the city solving a trail of clues sent to your phone, including riddles and puzzles in a treasure-hunt style format.

What phone number do I need to participate?

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

Do we play in teams, or as individuals?

You play in teams of 2–6 players. If you have a larger group, it can split into multiple teams that play head to head.

Are there breaks during the experience?

Yes. There are selected built-in break points. Food and drinks during breaks are at your own expense.

Is this a private experience?

Yes. Only your group will participate.

Is it available on public transportation and are service animals allowed?

The start point is near public transportation, and service animals are allowed.

If you want, tell me your travel dates and group size (ages included). I’ll help you pick the best time window and a strategy for sharing the phone among teammates.