Warning: full spoilers for Season 4 of Supernatural, including Episode 22, "Lucifer Rising".
Ruby convinces Sam Winchester that drinking demon blood is the way to defeat Lilith and prevent Lucifer's release. Her deception lies in what she conceals: Lilith's death is the last of the 66 seals keeping Lucifer imprisoned. Sam believes he is stopping the Apocalypse, but by killing the demon he completes the plan Ruby helped carry out.
The manipulation works because Ruby approaches Sam while he is vulnerable after losing Dean, offers him a power that appears to save lives, and turns the fight against Lilith into an urgent mission. The season reveals these steps gradually, particularly in Episodes 9, 21, and 22.
1. After Dean's death, Ruby becomes Sam's ally
At the end of Season 3, Dean goes to Hell because of the deal he made to save Sam. While his brother is gone, Sam desperately tries to bring him back, without success. Ruby returns to his life during this period. Flashbacks in "I Know What You Did Last Summer" (4x09) reconstruct what happened.
Ruby presents herself as a demon willing to help him confront Lilith. She saves Sam from an attack and begins training him to use supernatural abilities he already possessed. They also develop an intimate relationship. Sam has tangible reasons to trust her: Ruby appears when he is isolated, teaches him a way to keep hunting, and gives his anger over Dean's loss a direction.
That does not make his trust sound. The season finale changes the meaning of those gestures: help, training, and closeness were also ways of steering him toward Lilith.
2. Why does Sam drink demon blood?
Sam's power does not originate with Ruby. As a baby, he was given Azazel's blood, a fact connected to the psychic abilities he displayed before Season 4. Ruby exploits that condition and teaches him to use his powers against demons. Drinking demon blood then amplifies his strength until he can confront increasingly powerful enemies.
At first, Sam finds the justification morally persuasive: forcing a demon out with his mind can preserve its human host's life, unlike methods that also kill the possessed person. In "Metamorphosis" (4x04), Dean discovers that he is using these abilities and confronts him. Sam promises to stop but eventually returns to Ruby and the blood.
The issue becomes more than the danger of the abilities themselves. Sam grows physically dependent on the blood and psychologically attached to the feeling of power, while Ruby ties every new dose to the possibility of defeating Lilith. By "On the Head of a Pin" (4x16), his increased strength proves decisive against Alastair. Dean sees a dangerous transformation; Sam insists he is doing what is necessary to defeat a greater evil.
3. The lie about Lilith and the final seal
The plan as the Winchesters understand it is straightforward: Lilith is breaking the seals that imprison Lucifer, and stopping her before the last one should prevent his release. Ruby reinforces this interpretation by saying that only the first demon, Lilith, is connected to breaking the final seal. Sam concludes that killing her in time will end the threat.
The missing detail changes everything: Lilith does not need to survive to break the final seal. Her death itself is that seal. Ruby knows this and, in the finale, reveals that she secretly worked to free Lucifer. According to her, Lilith also knew Ruby's real role, while the other demons were unaware of the operation.
The strategy is especially effective because it relies on partial truths. Lilith really is central to the last seal, and Sam really can kill her. The mistake is the causal link Ruby encourages him to accept.
| Question | What Sam believed | What Ruby knew |
|---|---|---|
| Demon blood | It was a dangerous but necessary way to gain enough strength to defeat Lilith. | Dependence would keep him on the intended path toward Lilith's death. |
| Lilith's role | She had to be killed before she broke the final seal. | Her death was the final seal itself. |
| Outcome of the mission | Killing Lilith would prevent Lucifer's release. | Killing Lilith would free Lucifer. |
4. Dependence drives Sam and Dean apart
In "When the Levee Breaks" (4x21), Dean and Bobby lock Sam in Bobby's panic room to try to get him off demon blood. Withdrawal brings pain and hallucinations, making it clear this is not a tool he can simply put away. Castiel secretly releases him, following orders he does not explain to the brothers at that point.
Once reunited with Ruby, Sam drinks her blood again. She says very few seals remain and presents killing Lilith immediately as a supposed necessity. When Dean arrives to stop their partnership, Sam protects Ruby. Their argument turns physical, and Dean calls his brother a monster. Sam leaves with Ruby after being told never to return.
This break is not a side issue. Ruby succeeds in replacing Dean as the person Sam trusts just when he most needs to question the advice he is receiving. Even so, the story does not erase his choices: Sam lies, hides his blood consumption, and rejects his brother's warnings.
5. "Lucifer Rising": killing Lilith frees Lucifer
In Episode 22, Sam and Ruby locate a demon connected to Lilith. To gain enough strength for the confrontation, Sam agrees to go beyond the blood he has been receiving from Ruby, despite the cost to an innocent possessed person. He also hears an altered voicemail that sounds like Dean brutally rejecting him. In reality, Dean had tried to reconcile. The episode does not definitively identify who changed the recording, so the act should not be attributed directly to Ruby as a certainty.
Meanwhile, Zachariah reveals to Dean that factions in Heaven also want the Apocalypse to begin, confident they will win the war that follows. Castiel ultimately helps Dean try to reach Sam. The brothers' conflict, then, is not taking place apart from other forms of manipulation.
At the convent, Sam overpowers Lilith using his abilities. He hesitates when he hears Dean calling to him, but Ruby's pressure and Lilith's taunts push him to continue. Sam kills Lilith. Her blood marks the opening of Lucifer's prison, and Ruby celebrates the plan's completion.
Sam immediately realizes he has been deceived. Ruby claims that the blood alone did not determine everything and insists Sam made his own decisions. That is the manipulator's version, not an exoneration of her actions. When Dean finally gets inside, Sam holds Ruby while Dean kills her with the demon-killing knife. The brothers reunite too late to prevent Lucifer's prison from opening.
6. What does Sam's journey actually mean?
Ruby does not turn Sam into an obedient villain with a single spell. She exploits his grief, his desire to save people, and the insecurity of someone who has carried demon blood since infancy. Each step makes the next seem defensible, until Sam mistakes being able to kill Lilith for being certain he should do it.
The ending keeps two kinds of responsibility distinct: Ruby designed the trap and concealed the truth about the seal; Sam made the decisions that placed him inside it. That is why Lilith's death completes Ruby's plan while opening a new conflict for the Winchesters.
Sources and references
- Apple TV: Episode 4x09, I Know What You Did Last Summer
- Apple TV: Episode 4x21, When the Levee Breaks
- Apple TV: Episode 4x22, Lucifer Rising
- Super-wiki: detailed Episode 4x09 recap
- Super-wiki: detailed Episode 4x21 recap
- Super-wiki: detailed Episode 4x22 recap
- BuddyTV: When the Levee Breaks recap by John Kubicek
- BuddyTV: Lucifer Rising recap by John Kubicek
