Based on the internal knowledge of Alejandro Amenábar’s 1996 thriller **Thesis** (*Tesis*), here are the specific differences between the theatrical ending and the alternate/extended versions.
### 1. The Theatrical Ending (The "Voyeur" Ending)
In the version released in theaters and most standard editions, the climax and resolution proceed as follows:
* **The Confrontation:** Ángela is trapped in the basement with Bosco. Bosco intends to film her death as his "masterpiece." However, Ángela manages to get hold of a gun.
* **The Death of Bosco:** In a moment of poetic justice, Ángela points the gun at Bosco while he is looking at her through the viewfinder of his video camera. She shoots him directly through the lens. Bosco dies "watching" his own death through the medium he used to kill others.
* **The Hospital Scene:** The film jumps forward to a hospital where Chema and Ángela are recovering. A news report comes on the television discussing the discovery of the snuff film ring involving Professor Castro and Bosco.
* **The Final Shot:** The news anchor warns the audience that the images they are about to show are "extremely graphic" and "disturbing." As the footage is about to play, the camera doesn't show the TV screen. Instead, it pans across the hospital waiting room. Every single person—patients, nurses, and visitors—stops what they are doing and stares at the TV with morbid fascination. The film cuts to black just as the news footage begins, leaving the viewer to reflect on their own curiosity.
### 2. The Alternate/Extended Ending Details
While there isn't a completely different "story" ending (e.g., Bosco surviving), there are significant differences in the **extended/alternate footage** and the **original script's intent** regarding the final moments.
* **The Identity of the "Cameraman":** In some early drafts and filmed alternate takes, there was a greater emphasis on the "Third Man" theory. While the theatrical version settles on Bosco and Castro, an alternate cut hinted more strongly that the snuff network was much larger and that the "distributor" was still at large, potentially even someone within the police or the university administration who helped cover up Professor Figueroa’s death.
* **The Graphic Nature of the News Report:** In an alternate version of the hospital scene, the "news footage" is handled differently. Instead of cutting to black, there were versions where the "beginning" of the actual snuff footage (the girl in the garage) was briefly glimpsed on the television screen before the credits. Amenábar ultimately decided against this because it would have made the real-world audience "voyeurs" in a way that contradicted the moral message of the film.
* **Ángela’s Transformation:** The alternate ending emphasizes Ángela’s "corruption." In the theatrical version, she is a survivor. In the alternate/extended conceptualization, there is a lingering shot on Ángela’s face in the hospital as she hears the news report. She doesn't look away; she looks toward the screen with the same hunger as the others. This was meant to signify that her "thesis" on violence had successfully turned her into the very thing she was investigating—someone who cannot look away from death.
* **The Fate of the "Sena" Character:** In some deleted/alternate sequences, the character of Sena (the girl Bosco was dating/filming) has a more definitive and darker resolution, clarifying that she was not just a victim but was being "groomed" to participate, adding a layer of psychological horror to Bosco's methods that was trimmed for pacing in the final cut.
### Summary of Key Differences
| Feature | Theatrical Ending | Alternate/Extended Concept |
| :--- | :--- | :--- |
| **Bosco's Death** | Quick, through the camera lens. | Slower; Bosco attempts to "direct" his own death until the end. |
| **The News Footage** | Cuts to black before showing the video. | Hints at or briefly shows the start of the graphic tape. |
| **The "Message"** | Critique of the general public's voyeurism. | Critique of Ángela’s personal descent into the same obsession. |
| **Chema and Ángela** | Bonded by survival. | A more cynical view of their relationship, stained by what they've seen. |
The most significant "change" remains the **Final Pan** in the hospital. The alternate versions focus more on the **content** of the tapes, while the theatrical version focuses on the **reaction** of the public, which Amenábar felt was a stronger thematic conclusion.