Sylvia Thaw (Lady Thaw) was the greedy assistant in creating the rejuvenating device used and built by Richard Lazarus and had intended to use it for herself and to become very rich while selling immortality to the world. She didn't care about the potential risk to Lazarus' life, only that her investment might be wasted on a disaster.

She was also Mr Saxon's representative on the project. She believed she was not just a co-worker and she loved Lazarus though he didn't reciprocate.

Sylvia was aware of Lazarus' cruelty and observed that the process and his new found youth had only made it worse. When Lazarus mutated after his rejuvenation went faulty he drained the life out of Sylvia as he needed the energy for the mutation to stabilise. (TV: The Lazarus Experiment)

Community content is available under CC-BY-SA unless otherwise noted.