As a mysterious club owner seeks Elvis's help, a familiar voice sends a message about a door that can't be closed — and the key to keeping it open.

Elvis, Keta and Nancy cross into the underworld to find Ventura and bring him home. Elsewhere, a much older Mayakén displays disturbing powers.

The crew sets a trap to catch the monster with Lupe's help — and the last of the LDD. But Death is looking for Elvis while they wait.

A series of flashbacks to the past reveal what happened to Mayakén, shedding light on his unusual childhood.

With time running out to protect the portal, Elvis and friends join forces to infiltrate the Conclave — and free Mayakén.