When Jack receives a letter from Aleister Crowley, inviting him to ascend to the next degree, the Parsons must decide if Thelema is what they both want for their future. After uncovering the truth about Virgil during her purge sessions, Susan is forced to deal with the chilling revelation back in the real world. Richard and Jack finally find common ground, rallying the Suicide Club for a dangerous final demonstration to the military. For the demo, Jack has all he needs except for one crucial element: Ernest.

Susan and Patty's relationship reaches a breaking point when Susan learns of her sister's indiscretions - nevertheless, they must join forces to use Virgil as a means to an end. After Marisol receives devastating news, she gains a new perspective on her relationship with Richard. Jack has a chance to get back into the military's good graces, but the conditions may be too tough to swallow. Yet with the Magus in jail, Jack's power within the Agape rises to new heights; however, the arrival of a new prospective tenant at the Parsonage threatens to change all that. Season finale.

Jack sees his ambitions threatened as Agent Wallace grows increasingly suspicious of Jack's ties to Aleister Crowley. In an attempt to clear the air, Jack invites Wallace, General Braxton, and their military colleagues to the Parsonage for a summer dinner party - hoping to show them they have nothing to fear - but his best laid plans go awry as dark secrets are revealed and Ernest takes drastic steps to achieve transcendence.

Jack's conjuring of the Angel earns Ernest's loyalty but divides the Agape, spurring the Magus to investigate the so-called 'miracle.' Marisol attempts to confront her father about the secret that destroyed their family as Richard deals with his broken heart by diving deeper into the rocketry project. Meanwhile, when Susan's attempt to get Thelema officially recognized as a religion hits a roadblock, she turns to Ernest in hopes of putting a stop to Virgil's harassment once and for all.

Susan realizes Thelema might be the key to understanding her own psychological wounds. She attends the Agape Lodge for purge sessions with the Grand Magus, while Jack becomes increasingly disenchanted with the religion that promised so much yet delivered so little. Richard and the Suicide Club hit a massive stumbling block, forcing Richard to invite Jack and Susan out to a lavish dinner in an attempt to gain Jack's help. But Jack has been offered a promotion at Pueblo Powder and must decide between providing Susan with the life she always wanted or burying the hatchet with Richard to continue their rocketry dream.

Susan's concerns about Jack grow after she researches Aleister Crowley and confronts Maggie with the mysterious truths behind this cult religion. Susan's questions leave Maggie at a breaking point, forcing Ernest to confront his inner demons.

While Richard and the rocketry team abandon the Suicide Club for more conventional pursuits, Jack delves deeper into the world of Thelema and Sex Magick as a means to convince General Braxton that reaching the moon isn't just comic book fantasy. Susan's concerns about Jack grow after she researches Aleister Crowley and confronts Maggie with the mysterious truths behind this cult religion. Susan's questions leave Maggie at a breaking point, forcing Ernest to confront his inner demons.

Jack’s expert witness testimony at a high profile trial thrusts the rocketry team into the spotlight and helps land them a coveted invitation to The Athenaeum. Meanwhile, Virgil drops off Patty, Susan’s rebellious teenage sister, for a disruptive weekend stay, and Ernest’s wife, Maggie, makes a surprise return. When Jack’s evening at The Athenaeum doesn’t go as planned, Jack seeks out Ernest to blow off some steam and ends up on a dark detour into the Los Angeles underbelly.

In 1930s Los Angeles. Jack Parsons works as a janitor at a chemical factory by day, but, by night, he nurses a secret ambition: to build rockets that will take mankind to the moon. The pressures of his double life are further complicated when Jack and his wife Susan are confronted by a mysterious new neighbor, Ernest Donovan, who appears to be leading a double life of his own.

The U.S. Military offers Jack, Richard and the Aerojet team a classified mission that could turn the tide of World War II, but which comes with increased scrutiny of Jack's personal life. As Jack strives to straddle the worlds of mysticism and science, Virgil Byrne's crusade against the Agape Lodge forces Jack and Susan to offer the cult safe haven in their Pasadena mansion, only to have their lives further disrupted by the return of Ernest Donovan, who has come back to Los Angeles more broken than ever.