saki101

What a pleasure to find your comment this morning! As you see, I've gotten a bit more regular about posting again.

Without spoilers, some of your queries can be, at least partially, answered.

So M was contaminating people close to Sherlock (deliberately? and would contamination by Molly or John hurt him?)

In a sense Moriarty is contaminating them. The process isn't totally deliberate though as a loose bonding will happen automatically between people who are close to "one of the descendents of the original experiment" and have an affinity (in the ordinary sense of that word). Jim is using the process; although he cannot direct it, he can give it opportunity. If he can bind people to him, they might do things for him which would help him with his plans for Sherlock, but they wouldn't be a biochemical threat to Sherlock. Moriarty had been seeking an opportunity to start the process with Sherlock by being at Bart's and cultivating a relationship with Molly who he knew spent a lot of time with Sherlock and could introduce them. He is touchy with her, but he doesn't get to touch Sherlock. He might have hoped an introduction would lead to a handshake, but it didn't.

Going way back to Sometimes there are a few hints about it:

- ...the people whom he had already bound to him, albeit loosely. The "he" being Sherlock there.

and [Sherlock]...tried not to bind Molly any more closely to himself. He didn’t want her, but her adoration sweetened the air about her, made it hard to reject her unequivocally. No, he didn’t want Molly...

So Molly was one of the people at Bart's, like Mike, who were loosely bound to Sherlock and he was being careful not to bind her any more closely inadvertantly because she was very receptive. Despite this she doesn't have a rejection reaction to Moriarty's "contamination" because the bond is only a loose one with both of them. This doesn't totally explain what's going on because there is an extra piece of the puzzle that hasn't been explained yet, although it is coming up in the next section I post.

One of the ideas contributing to this notion came from the categorisation of relationships in common law into either affinity or blood. Affinity relationships are those created by marriage. I always thought it was a nice word for the distinction. With the individuals who can fuse, affinity relationships become a sub-category of blood relationships and even friendships will have this biological aspect to them.

Another looong answer from me! Thank you for asking them!