The saga of Agent Neve Errong concludes with this gripping tale of spies, mathematics, and danger. Eager fans have hungrily gobbled up the previous installments of this beloved cryptographical series.

1. The Adventures of Neve Errong Part III: Last Rites of E.V.I.L.L.

2. From the desk of The Chief Agent Errong, You have done tremendous work. The World Cup shall soon lie in deserving, sportsmanlike hands – but only after you wrest it away from those ruthless ruffians, the agents of E.V.I.L.L., who have stolen the Cup! We’ve tracked their trail so far to St. Paul’s Cathedral in London. We have another clue for you and brainy Agent Al Waysright, but this one’s a toughie... Use your thinking caps on this one – we have intercepted another coded message, but this time with no key! Good luck, Agent. The coded message is on the next page. Be sure to eat this message so it doesn’t get into enemy hands... You have been eating your messages, right??

3. The Coded Message MGPP HRWG RW JAREHEWQ YVG UVEGB JWH VEF JQGWYF! MG MEPP FEEW VJAG YVG UDL YJXGW RDY RB GWQPJWH. YVG BEWJP FYGL: TCEWQ YVG UDL YR YVG HRUXPJWHF JY ZEHWEQVY YRWEQVY. RDC ZGW MEPP MGJC RCJWQG FVRGF. KRD MGJC CGH RWGF. ??? A Cryptogram is a monoalphabetic cipher with no clues. Letter switches will always be the same, but we begin with nothing.

4. Cracking Cryptograms Letter Frequencies

5. A  2 B  3 C  6 D  5 E  11 F  8 G  21 H  6 I  0 J  12 K  1 L  3 M  6 N  0 O  0 P  9 Q  7 R  14 S  0 T  1 U  3 V  11 W  17 X  2 Y  13 Z  2 Applying Letter Frequencies MGPP HRWG RW JAREHEWQ YVG UVEGB JWH VEF JQGWYF! MG MEPP FRRW VJAG YVG UDL YJXGW RDY RB GWQPJWH. YVG BEWJP FYGL: TCEWQ YVG UDL YR YVG HRUXPJWHF JY ZEHWEQVY YRWEQVY. RDC ZGW MEPP MGJC RCJWQG FVRGF. KRD MGJC CGH RWGF. What do you notice about the frequency of letters in this coded message? What guesses do you think we can make?

6. Solving: Step One First, try replacing G  e MePPHRWe RW JAREHEWQ YVeUVEeB JWH VEF JQeWYF! Me MEPP FRRW VJAeYVe UDL YJXeW RDY RB eWQPJWH. YVe BEWJP FYeL: TCEWQ YVe UDL YR YVe HRUXPJWHF JY ZEHWEQVY YRWEQVY. RDC ZeW MEPP MeJCRCJWQeFVReF. KRD MeJCCeHRWeF. Cryptologists must also look at word and bigram frequencies. What do you notice? YVe appears quite frequently, even several times in the same sentence. What word would you guess YVe is?

7. Solving: Step Two ‘the’ occurs far more often than any other English word, especially when you consider only three-letter English words ending in ‘e’. Let’s assume that YVe=the MePPHRWe RW JAREHEWQ the UhEeB JWH hEFJQeWtF! Me MEPP FRRW hJAe the UDL tJXeWRDt RB eWQPJWH. the BEWJP FteL: TCEWQ the UDL tR the HRUXPJWHF JtZEHWEQhttRWEQht. RDC ZeW MEPP MeJCRCJWQeFhReF. KRD MeJCCeHRWeF. Now look at two letter words. What can we figure out from ‘RW,’ ‘Me,’ ‘RB,’ ‘tR,’ and ‘Jt’?

8. Solving: Step Three ‘Me’ could decrypt to ‘be,’ ‘me,’ ‘he,’ or ‘we.’ Not very helpful. ‘Jt’ could be ‘at’ or ‘it.’ Both are likely so we don’t want to assume anything. However, ‘tR’ only makes sense as ‘to.’ Replace R  o. MePPHoWeoWJAoEHEWQ the UhEeB JWH hEFJQeWtF! Me MEPP FRRW hJAe the UDL tJXeWoDtoBeWQPJWH. the BEWJP FteL: TCEWQ the UDL to the HoUXPJWHFJtZEHWEQhttoWEQht. oDCZeW MEPP MeJCoCJWQeFhoeF. KoDMeJCCeHoWeF. Look at the rest of the words. Are there any others that only makes sense as one word?

9. Solving: Step Four ‘FhoeF’ only makes sense as ‘shoes.’ Replace F  s MePPHoWeoWJAoEHEWQ the UhEeB JWH hEsJQeWts! Me MEPP sRRWhJAe the UDL tJXeWoDtoBeWQPJWH. the BEWJP steL: TCEWQ the UDL to the HoUXPJWHsJtZEHWEQhttoWEQht. oDC ZeWMEPP MeJCoCJWQe shoes. KoDMeJCCeHoWes. What words have we almost solved? ‘oW,’ ‘hEs,’ ‘oDt,’ ‘steL,’ and ‘oWes.’ All of these have more than one possibility. What guesses would you make, knowing what you know about word and letter frequencies?

10. Solving: Step Five and Six MePPHone on JAoiHingthe UhieBJnHhis Jgents! Me MiPPsRRnhJAe the UDL tJXenoDtoBengPJnH. the BEnJPsteL: TCingthe UDL to the HoUXPJnHsJtZiHnight tonight. oDCZen MiPPMeJCoCJnge shoes. KoDMeJCCeH ones. Assume that ‘oW’ and ‘oWes’ become ‘on’ and ‘ones’ rather than ‘or’ and ‘ores.’ ‘n’ is a more common letter than ‘r,’ and ‘ones’ is a much more common word than ‘ores.’ After that, ‘tonEQht’ looks like ‘tonight.’ Try replacing E  i and Q  g. Can you solve the rest on your own?! The next page has two hints, if you would like. Otherwise, good luck! Once you’ve finished solving, jump ahead to the Chief’s message.

11. Hint Page Hint 1: Return to letter frequencies. What frequently occurring letter have we not yet decrpyted? Does it make sense replacing frequently occurring ciphertext letters? Hint 2: Cryptologists might also search for frequently occurring bigrams, or pairs of letters. The most common double-letter bigrams are ‘ll’ and ‘oo.’ If you’re still having trouble, the solution is on the next page...

12. From the desk of THE CHIEF “well done on avoiding the chief and his agents! We will soon have the cup taken out of England. The final step: bring the cup to the docklands at midnight tonight. Our men will wear orange shoes. You wear red ones.” Agent Errong, Triumph! Thanks to your hard work, we can completely close the cup case. Finally, those felonious fiends at E.V.I.L.L. will spend some well-deserved time behind bars! They thought they had the better of us, but I sent out several teams of our agents, all wearing red shoes, ready to take out the agents of E.V.I.L.L. and step into their place. The nefarious ne’er-do-wells only looked for red shoes, so when our imposters arrived, they handed us the Cup and we handed them the cuffs! CONGRATULATIONS!