Dr. Andre Delambre aka (The Fly) is the main antagonist of the 1958 science fiction and horror movie of the same name,
Delambre was a kind and compassionate inventor who worked for the Air Ministry and had a loving marriage to his wife Helene, who later became his confidant - the only one to know about his experiments with the "transmitter", as he called it. Delambre spent months experimenting with the transmission of inanimate objects and animals, with some of the experiments having rather strange results. These included, for instance, an ashtray which came out reversed like in a mirror; and also Delambre's cat, Dandelo, whose structural pattern was never reconstructed, resulting in the animal effectively disappearing and never returning.
When Delambre did feel secure enough to test the machine on humans, he chose himself as the first subject. Unfortunately, a fly accidentally entered the transmitter with him, and the two got mixed together in an atomic level. The creatures that emerged on the receiving end of the transmitter where eerie human-fly chimeras. Delambre now had a giant dipteran head in place of his own and an insectile leg in place of his right arm. The fly, likewise, had a white humanoid head and leg.
Despite this, Delambre still kept his own brain and intellect, although he expressed concern that said intellect could "disappear at any moment". Due to his insect head he could no longer talk, and had difficulty seeing small objects. However, he was still capable of using a typewriter to communicate by leaving notes to Helene. At first he didn't reveal to her what had happened, telling her only that he had suffered an accident with the transmitter, and asking her to leave bowls of milk laced with rum for him to feed. When he allowed her to see him, he kept his head and right arm hidden beneath a velvet cloth, so she did understand that he was disfigured, although she couldn't guess the details.
Delambre claimed that it was imperative to find the fly with the abnormal white head and leg - as his only hope of returning to normal was passing through the transmitter with it -, but although Helene searched for it for many days, she still failed to locate it. Desperate, she plead her husband to try to enter the transmitter again, even without the fly, and see if he could be returned to normal. Delambre admitted that he had already tried that seven times, but agreed to undergo another attempt. Unfortunately, the result was even worse, as he was reconstructed with some facial features of a cat mixed up with those of the fly. Apparently, the transmitter had stored the structural pattern of the disappeared cat, Dandelo, and now used it to try to restore Delambre's missing parts.
When Helene finally saw what her husband had become, she agreed to put an end to his life as he wished, in a way that the world would never know about his experiments and never replicate them. Delambre put his head under the steam-hammer of his brother François' factory and asked Helene to operate the machine and crush it. After that she used it again to crush Delambre's insectoid right arm. As she confessed to having killed her husband with a steam-hammer, Helene was placed in an asylum and later committed suicide.
The fly, meanwhile, was caught on a spider web, as witnessed by François Delambre after he had read Helene's notes and became aware of the whole incident. Recognizing the fly as the same one that got mixed with his dead brother, François mercifully crushed it and placed it in a matchbox which he buried in the cemetery, next to his brother's body.