You're rummaging in the attic and among all the broken tennis racquets and back copies of What Caravan? you find an old share certificate.
What can you do with it?
The first thing is to find out if the company still exists and whether it's worth anything as a result.
Who knows? You might be the long-lost majority shareholder of a FTSE-100 company.
So contact the company registrar. If you don't know how to do that, get in touch with Companies House (0870 3333636).
They can let you know whether the company has changed its name or been dissolved. Their records go back about 150 years.
The Stock Exchange also has comprehensive records, including name changes, dating back 100 years.
The Stock Exchange Year Book, available at most large city libraries, gives contact information for most companies.
If that doesn't work you can ask a commercial company to do a search for you.
You'll have to pay, and most searches are fruitless.
Trust Research Services, for instance, charge around £50 for a search and say that about 80% result in finding the shares have no stock market value at all.
Most of the value is bound to be in its collectible value.
The art of share certificate collecting is called scripophily and it's quite a little hobby.
One such certificate is the debenture at the top of the page for the Thames Iron Works, which paid £4 a year.
The company built the first armoured iron hulled battleship, called the Warrior, which was launched in 1860.
Construction took place on the West Ham side of the River Lea - the works football team eventually changed its name to West Ham United.
This share certificate has no stock market value but as a collectable it's worth about £70.
Another share certificate for the London and Westminster Bank, which became the NatWest Bank, is worth about £45.
Obviously a certificate only has a value if someone is prepared to buy it.
Scripophily is relatively new in this country, but it's very popular in countries such as the United States and Germany.
Part of the appeal in the US is that share certificates were often very ornate.
Some, especially for railroads, were almost works of art, with detailed drawings and beautiful script.
And of course they might have immense historic value.
In 2000 a first issue of the Standard Oil Company from 1871 was sold for $134,000 (£93,000).
It helped that it carried the signature of John D Rockefeller, the company president.
Something like that can really boost the value of a certificate.
One of the important things about any certificate is its condition. This is graded on a six-point scale:
UNC - Uncirculated. Straight from the printers and still in perfect condition
EF - Extremely fine. You can hardly tell it's been handled
VF - Very fine. Signs of use such as a fold or slight discoloration, but still in very good condition
F - Fine. A bit worn and stained
Fair - Quite worn with some minor tears
VG - Stands for very good, but a misnomer. This will be badly damaged, torn or with pieces missing. Dealers and auction houses won't normally touch them.
If you want to become a scripophilist, how do you go about it?
There are some dealers who specialise in bonds and shares, while others handle them along with coins, paper money etc.
Auction houses in Europe and the US hold scripophily sales several times a year. You can obtain a catalogue and vote by post if you wish.
And, of course, there are many sites on the internet. Look at the links on the right of this page for some pointers.
You don't have to spend a fortune to get into scripophily. Good quality certificates can be had for under £100.
But heed the words of the International Bond & Share Society.
Your pastime might turn out to be profitable, but if you are in scripophily as an investment, you're likely to be disappointed.