Grimm - Trust Me Kno... Instant

Beyond the knot itself, this episode is critical for the introduction of other major magical artifacts:

If either person fails to fulfill their end of the bargain, an invisible force chokes them to death, mimicking the sensation of being hung by a noose. Grimm - Trust Me Kno...

The penalty is specifically triggered by the person who breaks the oath first . Context in the Series Beyond the knot itself, this episode is critical