A mystery you can solve only once can still be the better game for your group. The useful comparison is what you get to do before you know the answer.
Sherlock Holmes: Consulting Detective – The Thames Murders & Other Cases gives you ten authored investigations in Victorian London. Together, you choose people and places to visit, read what you discover, and build an explanation. The Search for Planet X gives competing astronomers a hidden arrangement of objects to deduce, with a companion app answering their information requests.
Both ask you to reason from incomplete evidence. Their differences become clearer at the moment you have a promising idea and must decide what to investigate next.
Consulting Detective: would another visit explain anything?
In The Thames Murders, visiting someone means finding an address in the directory and reading the corresponding passage in the case booklet. Newspapers can suggest leads; the map can help you check whether someone's movements make sense. You discuss discoveries together. The role of lead investigator passes around the table, and that player has the final choice of destination when opinions differ.
Consider a hypothetical investigation, unrelated to any case in the box. Two accounts seem to disagree about when someone arrived. You could visit another witness, hoping for a clearer account. Or you could reread the passages you already have and check the journey against the map's travel scale. Perhaps the contradiction disappears once you distinguish leaving one place from arriving at another.
Those choices feel different because visiting a location gives you an authored passage, not a custom answer to whatever question you have in mind. The witness might help. They might tell you something that changes which question you should be asking. Choosing a promising destination and interpreting what you find are both part of the investigation.
You can follow as many leads as you like, but the score later compares your lead count with Holmes'. Extra counted leads reduce it. Rereading visited passages, consulting the newspapers and discussing your theory are free.
That creates a useful pause before another visit: can you name the gap you're trying to fill? A new lead might earn points by helping you answer a question, yet cost points through the extra investigation. You can also decide that understanding the story is worth more to you than protecting the score. Agreeing on that preference helps prevent one person chasing closure while another is trying to beat Holmes.
Planet X: would this test distinguish the possibilities?
Planet X divides the sky into numbered sectors. Objects occupy those sectors according to rules, and you mark possibilities on a private note sheet. A survey tells you how many objects of a chosen type lie within a range of currently visible sectors. Other actions can reveal a sector's contents or a further rule about the arrangement.
Here, you choose the scope of the question much more precisely. Suppose you've located one comet in sector 7, and your deductions leave sectors 2 and 5 as the only possible locations for the other, with both visible. A comet survey covering sectors 2 through 5 will report one in either case. It confirms something you already know.
Survey sectors 2 through 3 instead, and the answer separates the possibilities. One comet puts it in sector 2; zero puts it in sector 5. Both surveys are legal, but the narrower one costs four units of game time rather than three. You're paying more for an answer that actually resolves your uncertainty.
Time affects turn order: the player farthest back on the time track acts next. An expensive question can therefore give rivals more opportunity to investigate before you act again. The satisfying choice is finding a test whose possible answers will help you enough to justify that cost.
Nor is the whole contest simply a sprint to the missing planet. Players score for correct theories about other objects, with bonuses for being first to submit them. Some theory checks eventually make information public. Correctly locating Planet X triggers the ending, but the winner is whoever scores most. You must decide which deductions to turn into points while the investigation is still moving.
What does the reveal use up?
In Consulting Detective, the group decides when to stop investigating, answers the case's questions, and reads Holmes' explanation. That ending lets you compare the story you reconstructed with the authored solution. Remembering that solution changes a return visit: you may enjoy seeing how the clues fit, but you can't count on having the same uncertainty again.
Planet X generates new arrangements under its logic rules. Knowing yesterday's locations doesn't solve today's puzzle. What carries forward is your method: choosing informative questions, combining answers and deciding when you know enough to commit. To locate Planet X successfully, you must identify both its sector and the objects in its two neighboring sectors.
Fresh arrangements are valuable if that recurring method is what you want to practice. They don't supply fresh characters, motives or testimony. Equally, ten authored cases don't become poor value merely because their answers are memorable. A group looking forward to discussing a particular mystery is getting something that another generated arrangement doesn't replace.
Choose the investigation you want to share
Choose The Thames Murders if the appealing part is putting accounts together aloud: noticing an inconsistency, proposing an explanation and deciding together whether another visit would help. Be comfortable with reading passages and with an ending that may leave your group pleased with its reasoning even when Holmes wins the score comparison.
Choose Planet X if you want your own deductions to compete with everyone else's. Expect private notes and private answers alongside public developments. Its repeatability is especially useful when you want to get better at asking questions, rather than move on to another authored crime.
Before treating replay count as the deciding feature, try describing the moment you'd most like to repeat. If it's the discussion that changes everyone's understanding of a witness, prioritize the cases. If it's realizing exactly which test will settle your remaining possibilities, prioritize Planet X.