If I had to criticize this, I'd say the set up leading to the dramatic confrontation between Lawrence and Horo was a tad contrived, given the fact that the revelation about Yoitsu happened exactly when Lawrence was taking part in a bet with a distinct possibility he could lose Horo and exactly when all the odds have started turning in Amarty's favour. I can see where they're going with this, and what they want to say about Lawrence and Horo's relationship at the other side of this arc
but I do think they could have done this without making it quite this forced.
Nonetheless, it is a very intensely dramatic set up they've got going here. I think this episode says a lot about Lawrence, and the number of different masters he serves. As his relationship with Horo deepens, it becomes more complex, as the number of secrets they hide from each other increases and he becomes more in tune with her sensitivities, etc. I think one of his "flaws" (in that, it's not really a flaw, but it can make their relationship more difficult) is that he approaches his relationship with Horo like he approaches his profession as a merchant, in that, lying and scheming (in appropriate amounts) lead to profit. He's not as open to Horo as he could be, and I think part of that is because he's in a profession where being "open" leaves you vulnerable. What we saw in this episode was pretty much the worst possible consequence of leaving Horo in the dark about Yoitsu, because Lawrence had no control over the circumstances in which she found out the truth (which, at this stage, as Lawrence has said, hasn't been confirmed, but given what most of the legends say, the possibility is pretty high), so he had no control over her reaction. Lawrence seems to be finding out that, sometimes, he has conflicting interests between maintaining his relationship with Horo and doing his job well (eg, "I've failed as a merchant" after he missed the boat on the pyrite while having fun at the fair with Horo.) There's almost this need for Lawrence to take his life and "simplify", but there's nothing simple when your job is a merchant (and the marketplace is so volatile) and your woman is a wolf goddess who will live forever. That's what makes this so dramatic.
But, I'm reasonably confident that
This is a genuine test for their relationship.