SECRET STOREROOM (Pages 80–81)

Using the encrypted dates along with any dates of birth you’ve already discovered, can you work out the dates of birth of all 8 suspects?

Bill Cooper – 22nd June 1868

Elizabeth Knight – 15th September 1871

Harriet Wheeler – 24th November 1882

Sam Cooper – 14th April 1901

Earnest Robinson – 31st January 1883

Stephen Cartwright – 4th January 1864

Mary Hawkins – 29th October 1889

Richard November – 6th August 1870

From your earlier visit to the Curator of Antiquities’ Office you know that Harriet Wheeler’s date of birth is 24th November 1882. From meeting Mary Hawkins you know her date of birth is 29th October 1889. Bill also tells you his birthday is 22nd June (and from the staff photographs you can also deduce Sam Cooper’s birthday is 14th April).

Using the information you already have you can start to decode the other dates of birth.

Harriet was born on the 24th, Bill on the 22nd and Mary on the 29th; in the encrypted version those dates are written as 91, 99 and 96 meaning:

9=2 1=4 6=9

You can extrapolate from this that the dates are encrypted using a substitution cipher where a string of numbers (in this case 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9) have been shifted in position to represent a different number in the same sequence (as shown below).