The contract The Levellers discovered in Kreig’s Puzzle Box, after (finally) recovering and opening it at the Citadel, following Xanthe‘s death:
Be it known to all that I, Thavius Kreeg, High Overseer of Elturel, have sworn to my master, Zariel, lord of Avernus, to keep the agreements contained in this oath.
I hereby submit to Zariel in all matters and for all time. I will place Her above all creatures, living and dead. I will obey Her all my days and beyond with fear and servility.
I recognize the dispensation of the device called the Solar Insidiator, hereafter called the Companion. In my capacity as High Overseer of Elturel and its vassal territories, I acknowledge that all lands falling under the light of the Companion are forfeit to Zariel. All persons bound by oath to defend Elturel are also considered forfeit. I further recognize that this dispensation will last fifty years, after which the Companion will return whence it came, taking Elturel and its oath-bound defenders with it, if that is Zariel’s wish.
All this is my everlasting pledge.