Probably Playfair
We have intercepted a message from one of the bad guys to another member
of his gang.
Because it’s in pairs of letters, it’s probably Playfair.
We overhead the sender pretending to order a large plain pizza,
so try “large plain pizza” as the key.
Decipher the message as soon as you can!
EG GY RB AL RD IE TG TL BQ WP KA LF LI BO RA QD AP LK KS RB TM AB ZW