I'm a bit stuck on what should be a straightforward plot issue but not sure what is actually realistic.

The character is going away into tera incognita (effectively exile until a deadly enemy has surely died, who will stop at nothing to hurt their family if it'll hurt the character). They may come back in 30 - 40 years time, if still alive. Or they may die alone; nobody at home will be aware either way. Essentially they will drop off the map and that's the end of all contact or knowledge of them unless by some chance they decide to return home in old age.

The character wishes to ensure a letter is delivered to their first grandchild (I'm handwaving away "what if their daughter doesn't have any children?") in about 40 years time. My question is, what would a realistic way be, to ensure this is done?

The story is set in the UK, in today's world. There's no magic or non-realistic elements, and the story gains a lot of its force from the care taken to research and portray matters accurately. It's also in a very "everyday" style, so it would be fine if they instruct some professional or put a document in a bank for storage. Money to pay for the service isn't a problem. What I'm stuck on is how they would actually do it, if someone really wanted to.

  • They can't leave it with family or friends. Family / friends might let slip, or it may be seen by someone or just be misplaced or forgotten over the years (if the person who knows about it has an accident). 40 years is a long time for someone to remember they have a thing to do.
  • If they wanted to leave it with a professional, the same applies - how would one be sure that a law firm would actually remember and not send the file out for shredding in 15 years? Do law firms ever have things on file to be done in decades time, in real life, or do they realistically require a person to contact them and remind/instruct them at the point in time when it needs doing?
  • Would it work to set up a trust with the law firm as trustee and an outside auditor, and an extra trust deed requirement that the auditor checks the trustees are acting as directed? So that the law firm would have to administer it and keep it "active", even if for 39.9 years all it did was pay legal fees? But if the law firm didn't, who would the auditors tell, or what could the character write into the instructions to deal with it?
  • Would one pay a law firm to check the file annually, or some such, just to ensure it was never archived or forgotten?
  • If not, what would someone do in today's society, if it really mattered?

The item - actually 2 items - to be delivered are the two halves of an encryption key + encrypted message pair. The character leaves the message to be delivered this way, by 2 routes that don't know of the other's existence, because then the 2 people/firms delivering them cannot read the message, since one only has encrypted text and the other only has an encryption key. But when the grandchild obtains both, they will be able to read the message, which directs them to any of 3 safety deposit boxes at different banks, all containing an identical envelope, and also tells them the code required to authenticate as the deposit box's owner. The latter part is easy since banks can be paid in advance (they hold mortgage documents for decades and at least one of 3 major UK banks will probably still be round, even if taken over, in decades time). But ensuring the messages will be delivered is less obvious.

Any help much appreciated, hopefully this is "in topic" to ask!

  • 2
    This is a "what to write" question because it's about brainstorming your specific plot, sorry. Feb 16, 2018 at 23:21
  • 1
    Is this better suited for Wolrdbuilding.SE? Feb 17, 2018 at 3:05
  • 1
    W.E. - not really, no "world building" is going on in the question. It's purely how to handle a common plot characteristic, which, when I looked closely, I'm not sure whether it can actually be done in the real world.
    – Stilez
    Feb 17, 2018 at 3:35

3 Answers 3


If you trust safety deposit boxes to last for decades when paid in advance, then arrange this service with the bank.

Hire a long established law firm (or two, for safety), that agree to a contract to perform this service for you in 10+ years.

Pay for a safety deposit box in advance 10+ years; with notification of additional fees due sent to an office in the law firm you hired. Typically you can list yourself as a co-owner, my wife and I are both signers for our safety deposit box.

Ensure the law firm can access it with just proof of their identity as one of the owners. Put your paid contract with them inside the safety deposit box, along with any items to be delivered.

The bank will not let your box just sit there without payment, they will notify the owner at the address given that rent is coming due (the law firm). The law firm will not just ignore the notice, they will investigate, know your name as co-owner, open the box, and find your contract. Even if they inadvertently destroyed theirs or lost it in a fire or move, yours should suffice, for such a small service, they will likely execute it. You could include cash or gold to cover any additional expenses they might encounter, such as discovering the proper recipient. Law firms are not in the business of ripping off clients, even if it is easy, they won't risk a scandal, and they have no idea if you are alive and could prove they violated their contract.

If you did this with TWO law firms, you increase the odds of success, and it certainly would not damage anything if the recipient received two (or more) copies of the same key, or same message.

  • 1
    > he will officially be recorded as overseas... Not necessarily; in most places no response to contact for 7 years or so allows a person to be declared legally dead, and any accounts or property they own abandoned, or if they have inheritors, the inheritors can take control of their estate. In some places the time limit is 20 years; it varies. en.wikipedia.org/wiki/Declared_death_in_absentia
    – Amadeus
    Feb 17, 2018 at 19:17
  • 1
    @Stilez I thought of another option. Do you have to explain it at all? Couldn't the granddaughter just get the letters and wonder aloud to the reader how her grandfather could have pulled it off? "He disappeared forty years ago, how did he know I'd even be born? Who sent the letters on his behalf?" Leave the reader to try and figure it out. Readers like that!
    – GGx
    Feb 18, 2018 at 8:51
  • 1
    @Amadeus Maybe I should have said I like it! But that's the thing ... it is possible. Sure, it could go wrong, but I think readers would be okay with it because it's not unrealistic. But, I completely agree, it won't work if grandpa is a crucial character or the MC and a big part of the puzzle. It would feel like a cheat. But no explanation might be better than a bad explanation?
    – GGx
    Feb 18, 2018 at 11:24
  • 2
    @GGx Regarding running something for a long time in the cloud, I have to point to a flaw in any such reasoning. Go back to 1978 (that's 40 years ago). The Apple II has just hit the market; the IBM PC has not yet been conceived of; typical home computer storage is audio casette tape; moderate-sized companies might have one computer (large ones will have one computer and lots of terminals attached to it); Microsoft is a dozen-employees company alongside famous ones like IMSAI or Cromemco. The Arpanet was barely a research project. TCP/IP didn't exist. What will change in the next four decades?
    – user
    Feb 18, 2018 at 12:11
  • 2
    @GGx "And it's a point that applies to almost any strategy that Stilez implements." Exactly. I could have gone on with relevant points in that comment, but I ran out of space. (Really; I had 0 characters left, and ended up trimming pieces here and there to make what I wrote fit.) I don't think the problem OP is looking to solve is unsolvable even in today's real world, but I do think that any solution will have to account for things that we don't yet even know that we don't know about. Ergo, it almost certainly has to be low-tech, simply because technology changes too quickly.
    – user
    Feb 18, 2018 at 12:29

I think that ensuring a letter is delivered is impossible. Around 99% chance of delivery is more likely.

There are two problems:

  • identification/authentication
  • delivery

The first problem reminds me of a study of personal identifiers. The study is from Sweeney (2009) and showed that using gender, ZIP code, and date of birth is enough to identify 87% of the American medical records. So, try limiting the personal identifiers. Knowing that the grandchild will be born in the next 30 years already helps.

If the grandchild's email address is known it becomes easy. Use a server to send an email. You can ensure delivery, but cannot ensure that it is read.

Hire a detective agency of some sort. Best way, I think, would be to let them track the mother. Provide them with the mother's social security number. You may also want to include an authentication method such as a DNA test. A grandfather-grandchild DNA match is different from a father-child DNA match. It is a like a modern variant of the glass slipper from Cinderella. Another approach would be using a necklace (or some family heirloom) that is passed on to the first born. Insert a micro-chip (such as a RFID) into the necklace and use that as an authentication method. The DNA and micro-chip method can both be used as a method of authentication without knowledge of the grandchild.

Once the target is identified you can choose a lot of methods for delivery. For instance, you can send flowers with a card in it. The message can be automatically appended to the card. Probably you want to wait till the kid is old enough, so you would have to delay sending the messages. Personally, I would use a distributed cluster-computer as opposed to a central server. Have the detectives do a yearly update in a strict digital form. They need to include the authentication of the grandchild. Then when the conditions are met, sent out your key and your message. For instance, sending the message by ordering flowers with a card and the key by sending a box of chocolates with a wishing card. If the bad guy is still keeping track of every gift the family receives, steganography can also help. Or conditional messages can help. Maybe let the necklace play an audio file when there is a certain trigger. Maybe the grandfather (or his digital representative) can send rare flowers with a certain smell that triggers the electronic nose in the necklace.

Payments can be done conditionally, for instance by using smart contracts. Or you could use a treasure hunt system, where participants have to perform actions (like lab rats) in order to reach the end goal. Downside/benefit of a treasure hunt is it is more public. It could be an interesting storyline.

The greatest problem I foresee, is why the grandchild would act upon receiving the messages. What is the motivation? Why check out the safety deposit boxes? Perhaps a new character can push the grandchild in the right direction.

  • A sort of treasure hunt could be explored. The old man could leave his daughter the first clue - something he asks her to hand down if she ever has a daughter. Have you seen FALLEN with Denzel Washington? I LOVE that movie. A dead man leaves a series of clues that lead a detective to figure out why he killed himself: a photograph, messages buried under paint, hidden books. It's well done and could inspire your thought process. And could be more interesting than using a lawyer or a computer.
    – GGx
    Feb 18, 2018 at 11:35
  • If the clues are interesting enough, it would also solve the problem Boondoggle has highlighted here: the grandchild would be motivated to act by the intrigue of the clues.
    – GGx
    Feb 18, 2018 at 11:39
  • In FALLEN it's the antagonist who initially motivates the protagonist to begin his search. You could explore a similar angle.
    – GGx
    Feb 18, 2018 at 11:40
  • 1
    "If the grandchild's email address is known it becomes easy. Use a server to send an email. You can ensure delivery, but cannot ensure that it is read." I don't know how many times over the decades I've got notices from people about them changing their e-mail address, typically because they change providers and didn't plan ahead for such an eventuality. Sure, Google and Microsoft (Gmail and Hotmail/Outlook, respectively) are big players today, but what's to say those will still be around in 40 years? What's to say that the person will still be checking that e-mail account in 40 years?
    – user
    Feb 18, 2018 at 12:24

If your character is influential (and I know this is a bit overkill), they could form something akin to a brotherhood whose sole purpose is to get this letter delivered (think Dan Brown's Priory of Sion who were dedicated to keeping Saunieres secret).

  • Just no. Forming a cult to deliver a message to a descendant is as you suspected, overkill :) The character is just an ordinary person, pretty much. Imagine something simple for any of us - suppose you wanted (for some weird reason) to be sure a treasured family photo was passed to a descendant, or some family history heirloom in many years time, without involving anyone who is family/friends.
    – Stilez
    Feb 18, 2018 at 17:06

Not the answer you're looking for? Browse other questions tagged or ask your own question.