Thralls
Thralls are special workers that assist you in constructing or upgrading your Stronghold's buildings. Hire an extra Thrall to add an extra construction or upgrade queue. With more than one Thrall, you will be able to upgrade or construct multiple buildings simultaneously.NOTE: If you already have the maximum number of Thralls allowed, purchasing additional permanent Thralls will REPLACE any temporary Extra Thralls you might have and will stay in your Stronghold forever.