The Infernal Egg (Transferred Custody) was handed over to Carlos and the Knights at the end of the day, when the astral incursion closed. The reason: the Guardian of Time is pursuing the group, and the Egg with the group is a bigger target.
The Knights will keep it in León until the group returns with information about the end of times. The risk is that incubation continues, and it is not known whether there is time for it to hatch.
See also
Spanish entry: Huevo Infernal (Custodia Transferida)