Jacques Ricciardo is vital to the storyline in The Human-Hybrid Project, although we never meet him, and he is mentioned only once.

Within the Corona Tower mainframe computer, Jantzen Hefferly's case file reveals the "catalyst" that vaulted him from stalled program participant to fully developed hybrid.

Ricciardo, an early participant in the program, was hybridized with gecko DNA for spontaneous limb regrowth. He balked at experiments to test his spontaneous limb regrowth and was reclassified as a failure. He was reassigned to Basement Level 5 for DNA harvesting.

Hefferly and Ricciardo were exceptionally close, and Ricciardo's demise nearly broke Hefferly.

It also initiated Hefferly's ability to sublimate directly from a solid to a gas and back again, proof that severe emotional distress could accelerate the change into full hybrid state, and is the reason Halo Sunchaser engineers Marisa Bruni's death in Book 7, The Rage. She is convinced the emotional trauma will vault Garik Shayk into his full hybrid state.

We first learn of Jacques Ricciardo in Book 9 of The Human-Hybrid Project, The Electrified Sword.