David Elster was the husband of Beatrice Elster, the father of Leo Elster, and the creator of the synths. He discovered what makes a human 'human' and hid the secret in the base code of a select number of conscious synths, including his son who died, but whom he brought back to life as a hybrid.
Pre Series Edit
David, Beatrice and Leo Elster moved to a large manor in the countryside due to David's dislike of attention and Beatrice's illness. Whilst at the manor, David created Mia to take care of Leo. She was the first sentient synth that he had created and after Mia's creation, David created Fred, Niska and Max.
His wife Beatrice escaped from her carers and took Leo with her to take her own life by crashing the car into a lake. Beatrice and Leo are both killed in the suicide but Mia brings Leo back to the surface after he dies. David brings him back to life by making Leo into a hybrid human-synth.
David later creates a new synth who is senient and identical to Beatrice Elster to replace her. However Leo and the other synths are horrified at Beatrice's replacement and David tells her to get out. He takes her to the woods to kill her but he can't and he returns back to his house. He tells Leo and the others to get out and he commits suicide.
David Elster cared a lot about his machines and once he had finished with one of the synths he moved onto the next one, when Fred said that David rarely taught them anything. Fred also mentioned that David underestimated Fred when Fred saved a dying fox from a certain death. David also tended to move on from a project once it was no longer new. David also sexually abused Niska, which is shown as when she said he didn't always treat her like a child.
- David was known to hide small messages in his work, such as when he hid his recipe for soup in a German synth which sold for 50,000 euros.