Pazzi Conspiracy
Plan C
Lorenzo was at the bottom of the picture
Giuliano was toward the top
Once at the cathedral, the large crowd naturally divided into smaller groups. Lorenzo went toward the front of the church, but others hung back. Someone was sent back to fetch Giuliano. Allegedly they embraced him in a show of affection but in fact to see whether he wore a breastplate under his tunic. He did not.
And a further complication now arose during these tense minutes. Count Montesecco flat refused to commit murder in the cathedral during Mass. Report of his attack of conscience comes from his own testimony, but it accords with his earlier reluctance and is not unreasonable to suppose. At any rate, he withdrew. He had been designated as the chief assassin of Lorenzo, so substitutes had to be found, and quickly. Two priests in the entourage, both of whom bore a grudge against the Medici, were chosen and were given knives. They worked their way toward the front, intending to attack from behind and in front.
Francesco Pazzi remained with Giuliano. The Archbishop never even came in, giving the excuse that his mother was very ill and that he had to go visit her. This much, at least, was according to plan, for his job was to take his mercenaries to the Palazzo de Signoria and secure the government there. The other main player was the elder of the family, Jacopo de' Pazzi, who was to take to the streets and cry out the deed once it was done. This, so the conspirators reasoned, would incite the populace to rejoicing that the tyrant was dead and to support of the Pazzi as liberators.
Some time during the frantic last-minute changes, the conspirators had had to decide on a moment to strike. The only signal they could choose was some moment during the Mass. Accounts vary but the one most commonly reported is that the signal was the elevation of the Host and the words asdfasdf that accompanied the elevation. This was a signal that could be both seen and heard, a necessity in that cavernous cathedral.