Maybe I Should Start from the End

Landon finds his mother, Seylah Chelon, and triggers the magical alert just before she knocks him out. While Seylah interrogates Landon, a merman attacks them. They escape with Hope and Alaric in pursuit, who learn a clandestine government agency is also looking for Seylah. Seylah accepts Landon is her son and reveals she once worked for the agency, bringing monsters to a facility containing a puddle of black goo. Anyone dropped into the goo would end up in Malivore, with all memories of them wiped from the public consciousness. When Seylah started asking questions, she was thrown into Malivore, too. She later found herself free and pregnant, eventually placing the baby into foster care. The merman tracks them to a motel and takes an Egyptian urn, revealed to be the second Malivore key, but he is killed before he can use it. Seylah helps Landon by returning to Malivore. Hope, whose memories are mysteriously intact, recounts the day's events to Alaric. They resolve to keep the urn safe while Hope and Landon officially become a couple. A government agent finds the photo of Seylah holding baby Landon and disposes of a witness into Malivore.

Plot summary from Wikipedia (CC BY-SA 4.0). Source