Supernova is the eighth installment in the Amulet series. The book was published by Scholastic on September 25th, 2018.
Trellis, looking for Emily in the Void, comes across an old hut, where he finds a mother elf and her son, starved and frozen. He soon finds out that the boy is alive and is his younger self, which means that the woman is his mother. Trellis wakes up to find (not done.)