The symbol is called a wolfsangel - here it is on the brick:

(It sounded like Monroe pronounced it woofs' anga)

We had so many storylines going in the episode ..

• Bud enlisting Trubel's services as a Grimm;
• The Luison tormenting his wife;
• Josh Porter pursued by Hundjagers;
• Renard telling Elizabeth about Kelley;
• Nick & Juliette's dilemma;
• MonRosalee targeted by Wesen KKK;
• Adalind's hallucinations (I think we can safely say, now, that's what was happening to her. There's probably no Hoffman, either.).

I had hopes Josh would become a Grimm. That looks very iffy now. Since his father died, the stressful run-in with the Hundjagers should perhaps have kicked-started his Grimm gene.
We'll see ..

Viktor won; Adalind is completely at his mercy now - and he's convinced her that all he wants is to get "our child" back.
Anyone who had a hand in helping her escape before the birth is going to be in terrible danger.

Taken altogether, it was a very exciting episode that sent a dozen balls rolling.
And only 3 more episodes until the mid-season hiatus!