MIGHTY THOR (1989) #483

Thor looks deeper into the mystery of the Don Blake construct; Riger finds Lokis wedding band inside the cave and goes to Asgard to ask him about it; He finds Sigyn standing in his way and an armored Loki who takes him to task for breaking his oath; Sigyn reveals that it was her that created the construct; She accidentally destroyed the real Don Blake when she sought to take him prisoner to force Odin to release Loki from the tree he had been imprisoned in; She replaced it with a construct so no one would know; When Thor and Blitziana go to leave, Sif decides she will go with him back to Earth.