The woman who tried to hypnotise us in the woods was the concubine. She was in the picture from the start. In the introduction we're told we have two half-brothers that
must have come from her.
You are told that you have two half brothers, whatever that may mean.
Then, out of nowhere, our previously amicable half-brother Eric suddenly is named a Knight of the Crown, gets legitimised, and furthermore there is talk of him getting lands, and now has a better claim than the entirely legitimate, child prodigy, business-savvy 13-year old that you are, further complicating the succession of the throne (remember the uncle).
The last bits of the month provide you with some news. Your half-brother, squire Eric has been named a Knight of the Crown, and there is very brief talk of him being provided with a bit of land before your father legitimizes him as his son. You double take at that bit of news.
Eric is older than you, and therefore has a better claim on the throne than you, though you are fairly certain he's poorly suited to such a task. Then there is the fact that Robilard is still the named crown prince.
Obviously with all these things to consider the king would never lavish Eric with all the titles and promises of land unless he for some reason legitimately thought bringing internal strife to Analysse was a good thing, or was hypnotised by his scheming, traitorous, magical concubine so as to place her own son on the throne.
Also, Erik used to think rather well of Raynor, thinking him a true brother and wishing to go with him to Koringberg:
"No way am i letting my little brother head out to the eastern borderlands without some decent protection, it's rough out there, i would go with you if i could."
to being somewhat reluctant to go with him on the same journey, just days after an assassination attempt. This change in behaviour happened within a mere few months and without clear reason. As far as we know nothing about Erik has changed politically. There
was talk of him getting lands but it doesn't look like that's really going anywhere, he isn't betrothed, his status as a Knight of the Crown is unchanged in any way, nothing. Really the only possible explanation is that his evil, lying, manipulative mother is badmouthing us, or brainwashing him. Seeing how she is often with Erik she has ample opportunity to to the former but also the latter.
Then there's the dreams:
You have dreams, very poor dreams.
Again your sleep is troubled by poor dreams, night terrors that sap the will.
The dreams could be interpreted as Arelar (the concubine) attempting to invade our mind, as in the woods. It could be she's trying to do the same but that the palace wards prevent her from "going all the way" as it were, or she could be playing it more subtly, sapping our will, which is detrimental to us for a broad number of reasons. If it's possible for us, a 13 year old boy who's magical ability is mostly self-taught, to bypass the many palace wards in our scrying it might also be possible for a more experienced magician (we really don't know much about the concubine, she might be) to invade our mind, if only to a lesser degree perhaps.