|“||If you aim to cheat the devil, you owe him an offering.||”|
James Delos is first seen visiting Sweetwater early in the the park's history. With the Hosts, including Dolores Abernathy and Teddy Flood frozen around them, James and William have a conversation about the potential of the park. William tells him that if James can't see the potential for data-mining of the guests, then he is not as good a businessman as he has heard. James likes William's courage at challenging him, and invites him to tell him what kind of ideas he has in mind.
Man in Black, and we find out that James is a host in whom they have implanted the memories of James as a test.
Host James appears to be lasting a number of days working fine, but eventually he breaks down and the Westworld staff have to burn down the apartment and start over again.
Eventually, William comes to the realization that trying to keep Delos immortal was a mistake, and leaves an unstable malfunctioning Delos to wreak havoc on his apartment, telling the technician to avoid incinerating him and keep him under observation for a few days.
Bernard and Elsie find a locked room in a secret lab in Sector 12, where host James is barely functioning after having been left alone for so long, having destroyed the most of the room and killed the technician.
|“||I'm all the way down now. I can see the bottom. Don't you want to see what I see?||”|
–James Delos's host, right before attacking Elsie.
Ford explains the immortality project to Bernard in the Cradle, noting that it's clear from James Delos's case that the project is a failure, as while the human mind can work just fine in the virtual environment, once it is placed into a host it degrades after a period of time.
The Forge takes the form of Logan Delos to tell Bernard and Dolores how it created the James Delos host, creating 18 million versions of him to find one that made the exact same decisions he made. It reveals that studying Delos caused it to come to the conclusion that human codes are not complex, but in fact embarrassingly simple: James Delos's code only amounts to 10,000 lines. In all the iterations of James Delos it tested, everything came back to one moment: only months before Logan's death by overdose, he had come to James in a last ditch effort for help. However, Delos turned him down, doubting Logan's sincerity. The guilt Delos felt haunted him for the rest of his life, and even affected his host: Logan's last words to his father, referring to the time when Delos tried to teach him to swim by throwing him into the pool, were the exact same words he said to Elsie and Bernard.
- Unknown illness (Off-Screen)
James Delos was known to be suffering from an unknown fatal illness (cancer was hinted) and he wanted to put his consciousness into a host before he expired to reach immortality. But the technology to accomplish that was not ready in Delos' time, and is still not proven to be ready many years after his death. James Delos is presumed permanently deceased in all forms.
- William (Caused)
- Delos technicians
Hybrid James Delos Build 1 - 148 were all incenerated after their test failed.
- Elsie Hughes (Out of Mercy)
After discovering the testing chamber, Elsie incinerates it with the last hybrid version of James to put him out of his misery.
This list shows the victims James' hybrid has killed:
- At least 5 unnamed Sweetwater residents (Simulation)
William and James have a close, but not tension free, relationship. James trusts William with his business when his health fails - rather than letting Logan run it.
Juliet is James Delos's daughter.
Logan is James Delos's son. After Logan's drug abuse, the two seem to have a tense relationship with James having disowned him.
Emily is James Delos's grand-daughter, Juliet and William's daughter, they seemed to have had a good relationship when she was a kid.
James Delos' hybrid version was tested and destroyed by fire after every fidelity test failure 148 times off-screen. The 149th version was destroyed on screen:
- Incinerated by Delos staff in a flashback, in The Riddle of the Sphinx
- Season Two
- Season Three
- "Decoherence" (simulation)