It’s interesting to note that, in series 3′s grand rule of three, we are introduced to three engagement rings. Three engagement rings for three doomed couples, in which, arguably, at least one person is “faking”: Mary & John, Molly & Tom, Janine & Sherlock.
We can also argue that in these 3 relationships, there is one person from the “good” side (John, Molly, Sherlock) getting engaged/proposing to someone most likely working with Moriarty. My belief is that Mary, Tom and Janine have all been deliberately placed on John/Molly/Sherlock to seduce and hurt them, also keeping them from developping an happy relationship with the person they have feelings for (Sherlock, Lestrade, John).
Love and committed relationships seem to be Moriary’s weapon of choice against his ennemies. Then again, his biggest threat consists in “burning the heart out of you”. It is interesting to note Jim knows how much love can hurt and destroy a person. An event from his own past?
Anyway, in series 3, we know of three engagements with people who have ties with Moriarty to hurt their significant other. We also get to see the three engagement rings, quite different from each other: three engagement rings telling us three different stories.
