Enquanto a mãe, o pai e os filhos enfrentam a hostilidade do seu novo coletivo ateu, Marcus propõe encher as paredes de uma antiga igreja com os adoradores do Sol.

Enquanto o coletivo tem a tarefa de caçar a serpente, a mãe é incumbida de reconciliar emoções complicadas. Convencido de que isso ajudará a sua causa, Marcus sai em busca da criatura antes que os ateus o façam.

Using his mysterious new powers, Marcus rescues a group of Mithraic prisoners, while Mother discovers the serpent is not a maneater but an herbivore. Father works through his frustration over Mother’s decision to spare the serpent’s life by engrossing himself in his work project, the regeneration of an ancient android.

After the Trust uses Paul to strike back against Marcus, Mother confronts the Trust and threatens a coup. Meanwhile, on the run from Mother, Marcus has to keep his followers from losing faith as his powers suddenly disappear.

Mother struggles to keep the collective from falling apart as she struggles to lead while Sue resorts to prayer in her desperation to cure Paul. Meanwhile, Marcus and his followers are given new hope as they discover an ancient temple. But as Marcus investigates the temple’s secrets, Decima and the rest of his followers are made to answer for their sins.

A reeling Marcus and Paul join forces with Mother to disarm the newly weaponized serpent before it wreaks unimaginable havoc.

Grandmother reveals her own agenda, Marcus seeks revenge, and Mother sets out to neutralize the serpent – but is leveled by the fallout.