At first, Helda and Skadi had never thought about the possibilty that a being would seek to take back a soul forever bound to Helda between the seventh circle of Hell, and therefore, no rules were written in the Covenant about it.
Not much informations are known about this first exception to the Covenant Helda made, except that it must have been concerning Orpheus and Eurydice, following the original Greek myth.
After he released the subvertio to protect the Gate of Time, the reformed Silver Blood Kingsley Martin trapped himself in Hell, beyond the seventh circle. Out of love for him, Mimi Force tried to find a way to get him out. But the first time she tried, she went with no soul to bargain, and her attempt therefore failed. She came back to Hell some time later, after having collected some informations from Ingrid Beauchamp (Helda's niece), this time with a mortal soul to exchange for Kinglsey. When she met Helda, the latter accepted the bargain, only to the condition Kingsley would be willing to leave. When Mimi convinced him, the three of them reached Helda's "office", where the bargain would be completed ; Oliver completely aware of what she had brought him down there for. But, in the end, she could not reconcile herself to sell "Oliver", so she proposed her own soul to Helda in the place of Oliver's.
- Payment : in order to complete the bargain, a soul must be given in exchange for the soul meant to be withdrawn form Hell.
- "No looking back" limitation : in order to complete the bargain, the soul trying to get out shall be willing to leave and shall not regret the decision to leave ; that is to say "no looking back".