There might literally not be any high level wizards or clerics with the requisite spells to make it safe, since they prepare their spells in the morning and already did so; it's not like Greater Teleport which you have other reasons to prepare. You'd probably want Teleport Trap to stop people teleporting in, which is seventh circle wizard and not prepared routinely, and plausibly Shield of Law or something which is cleric 8th. 

There might literally not be any high level wizards or clerics with the requisite spells to make it safe, since they prepare their spells in the morning and already did so; it's not like Greater Teleport which you have other reasons to prepare. You'd probably want Teleport Trap to stop people teleporting in, which is seventh circle wizard and not prepared routinely, and plausibly Shield of Law or something which is cleric 8th. 

- actually, Carissa is delegating, to the Most High and whoever is the most senior wizard now on site, thinking of the spells that their alter-selves would use to make an Ostenso expedition safe.