You've possibly done lots of multis where you have to find a plaque on the wall, detailing that something historical happened here one day a long long time ago, and to use the information to obtain the co-ords, etc etc etc.
Well this is another one of those, for which we make no apology. However, I think you'll want to pay a visit to this one.
Locate the plaque at the start co-ords and you will see a date. When taken in DD/MM/YYYY format, call this date AB/CD/EFGH, substituting the digits of the actual date on the plaque for the letters A-H. The cache can be located at :
N52 (E+H)G.D(D-B)(H+A) W0 (F-B)(G+C).D(E+G)A
We'd politely ask you don't post any spoilers as to the event in question in your logs, even encrypted. Otherwise people will go searching the internet to find out when this event happened, which will ruin the multi aspect of this cache and generally spoil it for everyone.
You'll need to bring your own pen. You're looking for a magnetic keyholder-type container.
The final location isn't suitable for wheelchair cachers I'm afraid, and is located about 10 minutes walk away.