Little is known about the Didact's current whereabouts or what his motives are, but these are his words to Sierra-117 (John)
"So fades the great harvest of my betrayal."
"Even these beasts recognized what you were oblivious to, human. Your nobility has blinded you, as ever."
"The Librarian left little to chance, didn't she? Turning my own guardians... my own world... against me. But what hubris to believe she could protect her pets from me forever. If you haven't mastered even these primitives, then Man has not attained the Mantle. Your ascendance may yet be prevented."
"Time was your ally, human, but now it has abandoned you. The Forerunners... have returned. This tomb...is now yours."