Refuge

This spell creates an item that triggers the spell’s full effects once the item is broken and a command word is spoken. Doing this allows the item’s user to summon the caster to her side or to transport herself to the caster’s abode. Assuming the caster lives in your stronghold, this can be a powerful, though expensive, tool.

You could use refuge to return to your stronghold. You could also give a refuge item to a scout or a guard at a remote watchtower so that he could report to you as soon as he ran into trouble. You could also use it to call your favorite spellcaster to you, but this requires additional bargaining with the spellcaster (and at least another 500 gp per level up front).

Casting: 2,410 gp (Clr13) or 3,030 gp (Wiz17) or 3,120 gp (Sor18)