It might seem rather plot-convenient that Kady could get rid of Psycho Fogg, by tricking him into drinking a flask of Archie-laced scotch without him being suspicious, but in various time lines Quentin was able to fool the Dean like this.
Sir Effingham calls for Julia to be assassinated, so Josh vows to do this dark deed upon his word as a devout Catholic - without mentioning that he's Jewish.
Cruel to be Kind Written by Nick Lowe and Ian Gomm Don't Give Up Written by Peter Gabriel
When Dean Fogg smells the scotch in the flask Kady gives him, he identifies it as "Isabella Islay's Single Malt," but he mispronounces "Islay," which any scotch enthusiast would know is pronounced "EYE-le."