So earlier I'd talked about how I was puzzled as to why Death at the start of the movie wants to kill only Antonius Block, but that by the end of the movie he takes everyone in Block's party, and I put out the hypothesis that perhaps Jons had caught the plague from the dead monk near the start of the movie, and subsequently passed it on to the other members of the party. There were a few flaws in the theory though, namely that if it were true the painter would have to die, it didn't account for the fact that Death comes for Block first (before he could have been infected by Jons) and that it did not account for the death of Jonas Skat as he didn't have contact with anyone "infected" before dying.
During the 22nd viewing I wondered instead if Block could possibly have been the original carrier. Suppose that he caught the plague upon his arrival to Sweden and Death comes for him because of it. Because of the reprieve caused by the chess match he's allowed enough time to touch Jons when he passes him food after the church scene, infecting him. Jons would then infect both Raval and the mute girl (whom I'll call MG from now on) by way of push and kiss respectively. Jons would then infect Plogg by way of a hug when he consoles him on the loss of his wife, Plogg would in turn infect Lisa when she kisses him, and Lisa would doom Skat when the actor pats her cheek before "killing" himself. Finally, Block himself would infect his wife Karin when he touches her hand near the end. Thus everyone that dies can be explained to have caught the plague, and the spreading traces itself back to a legitimate source in Antonius Block.
Still, though this theory explains why Death comes for Block first, it still leaves me unsatisfied. For one, it casts a very depressing pall over the entire movie because it means that Block is indirectly responsible for the deaths of all of his friends because he's too scared to accept his own Death at the beginning. There are also two fairly large problems left unreconciled. One, if Plogg were infected by Jons when they hug, he would have passed it on to Joff when he and Joff shake hands immediately after that scene. Joff survives, so that's a problem. Problem two has to do with the timing. Now it's fine to say that people die from the plague at different speeds, but in this construct Skat would have died mere seconds after catching it from Lisa, while Jons survives basically the entire film "infected". Block survives the longest, but I'm giving him a pass because he has the chess game to protect him.