What if one party to the contract is criminally detained?

If it is administrative detention, it will take ten days, and you can wait for the other party to come out and deal with it. If it is a criminal detention, it can't be released in a short time, either the other party entrusts an agent to handle it, or it can only be prosecuted through the court, which is compulsory.

The event referred to by force majeure must be unforeseeable by both parties at the time of conclusion of the contract, and it is purely accidental after the conclusion of the contract. If there is a possibility of an event before or at the time of concluding the contract, and the parties can meet the event, then the event, no matter how helpless the parties are, does not constitute a force majeure event.